Contents 1. Mobile Devices ................................................................................................................... 3 2. Networking ......................................................................................................................... 5 2.1 Ports and Protocols .......................................................................................................... 5 2.2 Network Devices ............................................................................................................ 16 2.3 SOHO Networks (Small Office Home Office) .............................................................. 27 2.4 Wireless Networks ......................................................................................................... 37 2.5 Network Services ........................................................................................................... 49 2.6 Network Configurations................................................................................................. 57 2.7 Internet Connections ...................................................................................................... 70 2.8 Network Tools ............................................................................................................... 78 3. Hardware .......................................................................................................................... 85 3.1 Cables and Adapters ...................................................................................................... 85 3.2 Connectors ................................................................................................................... 113 3.3 Memory ........................................................................................................................ 122 3.4 Storage ......................................................................................................................... 131 3.5 Motherboards, CPUs, and Add-on Cards .................................................................... 142 3.6 Peripherals.................................................................................................................... 183 3.7 Power ........................................................................................................................... 193 3.8 Custom PCs.................................................................................................................. 198 3.9 Common Devices ......................................................................................................... 203 3.10 SOHO Multifunction Devices.................................................................................... 207 3.11 Print Technologies ..................................................................................................... 212 4. Virtualization and Cloud Computing ............................................................................. 231 4.1 Cloud Computing ......................................................................................................... 231 4.2 Client-side Virtualization ............................................................................................. 240 5. Hardware and Network Troubleshooting ....................................................................... 245 5.1 Troubleshooting ........................................................................................................... 245 5.2 Troubleshooting Computer Hardware ......................................................................... 251 5.3 Troubleshooting Hard Drives ...................................................................................... 262 5.4 Troubleshooting Video and Display Issues ................................................................. 267 5.5 Troubleshooting Mobile Devices and Laptops ............................................................ 270 5.6 Troubleshooting Printers .............................................................................................. 281 5.7 Troubleshooting Networks........................................................................................... 286 1. Mobile Devices PRL – Preferred Roaming List Allows your phone to connect to the right tower Updates Over the Air (OTA) PRI – Product Release Instructions Radio Settings such as ID numbers, network codes, country codes Updates Over the Air (OTA) IMEI – International Mobile Station Equipment Identity Identifies a physical mobile device IMSI – International Mobile Subscriber Identity Identifies the user of a mobile network (SIM Card) Configuring Email on Mobile Devices POP3 – Post Office Protocol 3 Used for downloading and deleting mail from ISP server Name of POP3 Server, Username and Password Defined by mail provider, Port: tcp/110 POP3S for SSL (Secure Socket Layer) encryption, Port: tcp/995 IMAP – Internet Message Access Protocol Access mail on ISP central server Mail is usually stored on the server Supports folders and server-side searching Name of IMAP4 server, Username and Password Defined by mail provider, Port: tcp/143 IMAPS for SSL (Secure Socket Layer) encryption, Port: tcp/993 SMTP – Simple Mail Transfer Protocol Used for sending mail from a device to a mail server or between mail servers Usually, must send from a local or trusted device Authentication usually required, but may be different credentials than the incoming mail SMTP that required no authentication, relatively unused, Port: tcp/25 SMTP with authentication, Port: tcp/587 Microsoft Exchange Other than email, can also use for contacts, calendars, reminders Email, server, domain, username and password There is an integrated message encryption - S/MIME (Secure/Multipurpose Internet Mail Extensions) - Encrypt and digitally sign 2. Networking 2.1 Ports and Protocols IP – Internet Protocol Efficiently move large amounts of data from one IP address to another IP address Runs through network Ethernet, DSL, Cable systems Encapsulated by the IP is the TCP (Transmission Control Protocol) or UDP (User Datagram Protocol), occurs at OSI Layer 4 (Transport) Multiplexing is the ability to use many different applications at the same time over the same connection with TCP and UDP Ethernet Frame (Example for HTTP application data that is being sent to a web server): TCP – Transmission Control Protocol Connection-oriented A formal connection to setup the connection and close the connection It is a “reliable” delivery - Recovery from errors - Manage out-of-order messages or retransmissions When TCP data is being transmitted from point A to point B, there will always be an acknowledgement from point B that the data is received If there is no acknowledgement from point B, the data will be retransmitted from point A Flow Control - The receiver can manage how much data is sent UDP – User Datagram Protocol Connectionless as there is no formal open or close to the connection - Data is just simply being sent from point A to point B “Unreliable” delivery - No error recovery - No reordering of data or retransmission as there is no acknowledgement No flow control - Sender determines the amount of data transmitted IPv4 Sockets Server IP address, protocols, server application port number Client IP address, protocols, client port number Non-ephemeral ports (permanent port numbers) Usually are Ports 0 to 1,023 Usually on a server/service Ephemeral ports (temporary port numbers) For server to communicate back to the client Usually are Ports 1,024 to 65,535 Determined in real-time by the client Only for that particular session Most servers (services) use non-ephemeral (permanent) port numbers, but that is not always the case Port numbers are for communication so that clients and servers know where to send the data, not security Service port numbers needs to be “well known” for the client side For example: tcp/80 for web servers Ports on the network example: - Web server – tcp/80 - VoIP server – udp/5004 - Email server – tcp/143 - The source port which is the client’s port is randomly chosen for that session so that the server knows where to communicate back to the client for the particular service Common Network Ports FTP – File Transfer Protocol - tcp/20 (active mode data) - tcp/21 (control) - Transfers files between systems - Has security built in, and able to configure and authenticate with username and password o Some systems support a generic/anonymous login, with any password - Full-featured functionality such as list, add and delete etc SSH – Secure Shell - tcp/22 - Encrypted communication link - Login to devices remotely - Console access Telnet – Telecommunication Network - tcp/23 - Some older equipment only supports Telnet and not SSH - Same usage as SSH - Not encrypted, in-the-clear communication - Not the best choice for production systems as it is not encrypted SMTP- Simple Mail Transfer Protocol - tcp/25 - Server to server email transfer - Also used to send mail from a device to mail server o Configured on mobile devices and email - If you are receiving email, probably using IMAP4 or POP3 DNS – Domain Name System - udp/53 - Converts domain names to IP address - As they are very critical resources, multiple DNS servers are in production HTTP and HTTPS – Hypertext Transfer Protocol / Hypertext Transfer Protocol Secure - HTTP – tcp/80 - HTTPS – tcp/443 - Web server communication in the browser and by other applications - HTTP is in-the-clear communication, while HTTPS is encrypted POP3 – Post Office Protocol version 3 - tcp/110 - For receiving emails from an email server - Basic mail transfer functionality IMAP4 – Internet Message Access Protocol version 4 - tcp/143 - Includes management of email inbox from multiple clients RDP – Remote Desktop Protocol - tcp/3389 - Remote desktop services on many windows versions - Can connect to an entire desktop or just an application SMB – Server Message Block - Protocol used by Microsoft Windows o File Sharing, printer sharing o Also called CIFS (Common Internet File System) - Modern Windows direct communication over tcp/445 (NetBIOS-less) o Direct SMB communication over TCP without the NetBIOS transport - Older Windows uses NetBIOS over TCP/IP o udp/137 – NetBIOS name services (nbname) o udp/138 – NetBIOS datagram services (nbdatagram) o tcp/139 – NetBIOS session services (nbsession) AFP – Apple Filling Protocol - tcp/548 - File services in macOS - Works with SLP (Service Location Protocol) o tcp/427 and udp/427 - File management like copy, move and delete files DHCP – Dynamic Host Configuration Protocol - udp/67 and udp/68 - Automated configuration of IP address, subnet mask and other options - Requires a DHCP server o Server, appliance, integrated into a SOHO router etc - Dynamic / pooled o IP address are assigned in real-time from a pool o Each system is given a lease and must renew at set intervals - DHCP reservation o Addresses are assigned by MAC addresses in the DHCP server, and assign the same IP address to that MAC address every time o Quickly manage addresses from one location LDAP – Lightweight Directory Access Protocol - tcp/389 - Store and retrieve information like username and passwords in a centralised network directory/database to provide authentications o Commonly used in Microsoft Active Directory SNMP – Simple Network Management Protocol - Queries: udp/161 - Traps: udp/162 - Gather statistics from many network devices for network administrators - Version 1 – the original o Structured tables (1 query at a time) o In-the-clear communication (not encrypted) - Version 2 – A good step ahead o Data type enhancements o Bulk transfers (can query about many stuff) o Still in-the-clear communication (not encrypted) - Version 3 – A secure standard (commonly used) o Message integrity o Authentication o Encryption 2.2 Network Devices NIC – Network Interface Card The fundamental network device Every device that needs a network connection has a NIC Specific to network type - Ethernet, WAN, wireless, etc Often built-in to the motherboard or as an expansion card Many options such as single port, multi-port, copper, fiber Repeater Receive signal, regenerate, and resend it out - No forwarding decisions to make Common use - Boost copper or fiber connections - Convert one network media to another - Extend wireless network reach Hubs “Multi-port repeater” Traffic going in one port is repeated to every other port Everything is half-duplex - Two devices cannot communicate at the same time. - Once one of the devices is done sending information, another device can then begin sending information Becomes less efficient as network speeds increase/or more devices connected 10 megabit / 100 megabit Difficult to find today as it is too slow as more devices are connected to the network Bridge Connect the hub networks together using bridges - Can connect to different physical networks and topologies - Gets around physical network size limitations / collisions Make decisions on what traffic should be forwarded through the bridge based on the destination MAC addresses that is inside the ethernet frame Imagine a switch with 2 to 4 ports Distributes traffic based on MAC addresses Makes forwarding decisions in software An example of a modern bridge is a wireless access point (WAP) - Where on one side you have your wireless network, and it is connected to the ethernet wired network on the other side - The wireless access point is deciding based on the destination MAC address of the traffic it receives, and deciding whether it should forward it to the wireless network or the ethernet wired network Switches Bridging done in hardware - Hardware is ASIC – Application-Specific Integrated Circuit - Forwards traffic based on data link address (MAC address) Many ports and features - The core of an enterprise network - May provide Power over Ethernet (PoE) Multilayer switch / Layer 3 switches - Includes both switching and routing functionality within the same device o Routing functionality is making forwarding decisions based on destination IP address Unmanaged Switches Very few configuration options, plug and play Fixed configuration No VLANs (Virtual Local Area Network) Very little integration with other devices - No management protocols o If you want the switch to communicate back and forth to a management station via SNMP (Simple Network Management Protocol), you wouldn’t use this switch Low price point, simple is less expensive Managed Switches VLAN (Virtual Local Area Network) support Traffic prioritization Interconnect with other switches via 802.1Q E.G. Voice traffic gets a higher priority Redundancy support - Spanning Tree Protocol (STP) External Management SNMP – Simple Network Management Protocol Port mirroring for troubleshooting on the switch - Can connect a network analyser to one of the ports on the switch and capture packets from any other port on the switch to watch the traffic flow across the network Routers Routes traffic between IP subnets - Makes forwarding decisions based on IP address - Routers inside of switches are referred to as multilayer switches / “layer 3 switches” Often connects diverse network types - LAN, WAN, copper, fiber WAP – Wireless Access Point Not a wireless router A wireless router is a router and a WAP in a single device WAP is a bridge, and it extends the wired network onto the wireless network, and makes decisions based on MAC addresses Wireless LAN Controllers Centralized management of WAPs - Commonly used in large organisations to manage access points throughout the building. E.G university building with large number of WAPs - Allows a single “pane of glass”, which is a central management console that presents data from multiple sources in a unified display Management functions - Deploy new access points - Performance and security monitoring - Configure and deploy changes to all sites - Report on access point use Usually a proprietary system - If you are using a CISCO access point, you will probably be using a CISCO wireless LAN controller The wireless controller is paired with the access points Can also be cloud-based - Connect to the cloud-based controller and manage the console from anywhere Firewalls Filters traffic by port number - OSI Layer 4 filtering (TCP/UDP) o Some firewalls can filter based on the application Can encrypt traffic into/out of the network Protect your traffic between sites Some older firewalls can proxy traffic - A common security technique - They sit in the middle of the communication. o If you want to surf the website, you would send that request to the firewall, the proxy firewall will then make the request for you, receive the response, check through the response to make sure its appropriate for you to view, then send the traffic to you Most firewalls can be layer 3 devices (routers) - Usually sits on the ingress/egress of the network Cable Modem Broadband - Transmission across multiple frequencies - Different traffic types Data on the “cable” network - DOCSIS – Data Over Cable Service Interface Specification - Coaxial Cabling, shared bandwidth High-speed networking - 4 Mbits/s through 250Mbits/s are common - Gigabit speeds are possible Multiple services - Data for our internet connection, voice for telephone communication, and video for cable television DSL Modem ADSL – Asymmetric Digital Subscriber Line - Uses telephone lines instead of cable for cable television - Twisted-pair copper cabling, dedicated bandwidth Download speed is faster than the upload speed (Asymmetric) - ~10,000 foot distance limitation from the telephone company’s central office (CO) - 52 Mbit/s downstream, 16 Mbit/s upstream are common - Faster speeds may be possible if closer to CO Cable Infrastructure in an Office Patch Panels Combination of punch-down blocks and RJ-45 connectors Runs from desks are made once Permanently punched down to the patch panels Patch panel to switch can be easily changed - No special tools - Use existing cables Power over Ethernet (PoE) Power provided on an Ethernet cable - One wire for both network and electricity - For phones, cameras, wireless access points (WAPs) - Useful in difficult-to-power areas Power provided at the switch Switch does not provide power Built-in power – Endspans Connect a device in the middle, In-line power injector – Midspans Commonly marked on the switch or interfaces with PoE Ethernet over Power (EoP) Also called PLC – Power-Line Communication - IEEE standard 1901 500 Mbits/s Standard includes links to the premise, intra-building networking, vehicles, smart energy devices, etc 2.3 SOHO Networks (Small Office Home Office) The SOHO Router An all-in-one device - Modem - Router - Switch - Wireless Access Point (WAP) - Firewall, etc Routing and Switching Routing to the outside world Switching for local devices - WAN / DSL port One VLAN / LAN1, LAN2, LAN3, LAN4, etc Not much to configure - Routes and switches by default Access Points Settings Enable or disable frequencies - 2.4 GHz and/or 5 GHz - Available options will depend on the wireless standard used Configure SSID - May need a separate SSID for each frequency Security mode - WPA2 encryption preferred - Pre-shared key or Enterprise where everyone will have their own username and password to access the wireless network Channel / Channel bandwidth - Automatic / other nearby networks IP Addressing WAN interface - Automatically assigned via DHCP from the ISP - May require authentication into the router’s configuration before its able to be used on the network LAN interface - The SOHO router acts as its own DHCP server for the LAN - Internal IP address and subnet mask of the router is automatically assigned by the router through DHCP - DHCP address range for other devices - DNS server addresses, if not configured will use the same DNS configuration as the WAN NIC Configuration Wired - May not have many options to configure - Ports configured for auto speed and duplex - Speed: 10 / 100 / 1000 Mbit/s - Duplex: Half / Full Wireless - Enable / Disable wireless adapter - Find the network SSID - Key in password to access the wireless network End-user Device Configuration Automatic - Auto speed and duplex - DHCP Addressing End-user device configures based on router - IP address - Subnet mask - Default gateway - DNS servers IoT (Internet of Things) Configurations Internet of Things - Home Automation, mostly wireless through 802.11, which security is an issue Devices: - Thermostat - Light switches - Security cameras, Door locks - Voice-enabled smart speakers / digital assistants Almost all devices communicate outbound - No special port mapping / NAT (Network Address Translation) configurations required - Connect to a central server to gain access to these devices Firewall and DMZ Ports Every SOHO router is also a firewall - No external device can directly access the internal network - This normally can’t be disabled Some firewall in SOHO routers allow DMZ ports to be configured and allow unrestricted access - Consider creating more specific port forwarding rules, or don’t allow DMZ ports at all as it is generally a bad idea NAT – Network Address Translation IPv4 supports around 4.29 billion addresses, but there are over 20 billion devices connected to the internet around the world and growing at a rapid speed The address space for IPv4 is exhausted, meaning there are no more available addresses to assign to individuals This is where NAT come into play, however, this is not the only use of NAT NAT is an always-on functionality that is inside the SOHO router Configuring NAT For SOHO devices, this is automatic - Source NAT, also called PAT – Port Address Translation - All internal devices are translated to a single external address, and to the internet it all looks like 1 device Port Forwarding Also called Destination NAT or Static NAT - Destination address from the inbound traffic is translated from a public IP to a private IP - Does not expire or timeout, so anyone who accesses that IP address and port number externally will always have access to that particular server on the internal network External IP/port number translates to an internal IP/port 24x7 access to a service hosted internally Does not have to be the same port number Web server, gaming server, security system, etc This allows your internal device to be available externally UPnP – Universal Plug and Play Allows network devices to automatically configure settings on the SOHO router and find other network devices Sometimes also known as “Zero-configuration” Applications on the internal network can open inbound ports using UPnP - Instead of manually creating port forwarding rules, applications can communicate directly to the SOHO router to enable or disable the access for certain port numbers - Ports are only open when using that particular application, and when those particular applications are closed, those particular ports are disabled on the router - Security concern as we do not have direct control over when certain ports are open or closed - No approval needed - Used for many peer-to-peer (P2P) applications Best practice would be to disable UPnP, and have all of your configurations done manually through port forwarding Whitelist / Blacklist Content filtering and/or IP address ranges Whitelisting - Nothing passes through the firewall unless its approved - Very restrictive Blacklisting - Nothing on the blacklist is allowed - Specific URLs - Domains - IP addresses MAC Filtering Media Access Control address (MAC address) The “hardware” address Limit access through the physical hardware address (MAC Address) - Keeps the neighbours out - Additional administration with visitors as you would have to add the MAC addresses of your visitors so that they can gain access to your network Easy to find working MAC addresses through LAN analysis - MAC addresses can then be spoofed to gain access to the network - Free open-source software Not a good security, basically none at all (Security through obscurity) Wireless Channels and Encryption Configure for the highest encryption possible - WPA2-AES (Advanced Encryption Standard) is the best option - Choose WPA2 over WPA (Wireless Protected Access) - Older wireless routers might have WEP (Wired Equivalent Privacy), but it is not a safe option as it has quite a number of vulnerabilities Check your devices if you have more than one wireless access point (WAP) and ensure that all of them allow the highest encryption which is WPA2-AES Use an open frequency (channel) - Make sure it’s not conflicting with other devices or WAP in your area - Some access points will automatically find good frequencies - Channels 1, 6, 11 Managing QoS (Quality of Service) Some SOHO routers allow you to change the priority of your traffic - You may want to change the VoIP priority to high, and world of warcraft to low Prioritize applications, port numbers, IP addresses, or MAC addresses Or vice-versa A feature of high-end SOHO routers Be careful as you can accidentally cause applications that needs the highest priority to slow down 2.4 Wireless Networks Wireless Standards Wireless networking (802.11) Many updates over time Managed by the IEEE LAN/MAN Standards Committee (IEEE 802) Check with IEEE for the latest updates The Wi-Fi trademark - Wi-Fi Alliance handles interoperability testing 802.11a One of the original 802.11 wireless standards Released in October 1999 Operates in the 5 GHz range - Or other frequencies with special licensing 54 Mbit/s Smaller range than 802.11b - Higher frequency is absorbed by objects in the way - Many rules-of-thumb calculate 1/3 the range of 802.11b or 802.11g Not commonly seen today 802.11b Also an original 802.11 standard - Also released in October 1999 along with 802.11a Operates in the 2.4 GHz range 11 Mbit/s Better range than 802.11a, although slower Less absorption problems More frequency conflict - As it is used in many devices like baby monitors, cordless phones, microwave ovens, Bluetooth 802.11g An “upgrade” to 802.11b - Released in June 2003 Operates in the 2.4 GHz range 54 Mbit/s - Same as 802.11a (but a little bit less throughout) Backwards-compatible with 802.11b Same frequency conflict problems as 802.11b 802.11n The update to 802.11g, 802.11b, and 802.11a - Released in October 2009 Operates at 5 GHz and/or 2.4 GHz 150 Mbit/s per stream (600 Mbit/s total) 40 MHz channel widths 40 MHz mode and 4 antennas 802.11n uses Four MIMO (Multiple-Input Multiple-Output) streams - Multiple transmit and receive antennas 802.11ac Significant improvements over 802.11n Released in January 2014 Operates in the 5 GHz band - Less crowded, more frequencies (up to 160 MHz channel bandwidth) 866.7 Mbit/s per stream (Around 6.8 Gbit/s total) Increased channel bonding Larger bandwidth usage Changed to denser signalling modulation - Faster data transfers Eight MU-MIMO (Multi-User MIMO) streams 802.11 Summary Table 802.11 Technologies Frequency 2.4 GHz or 5 GHz, and sometimes both Channels - Groups of frequencies, numbered by the IEEE - Non-overlapping channels would be necessary Bandwidth - Amount of frequency in use - 20 MHz, 40 MHz, 80 MHz, 160 MHz 802.11 Channel Bandwidths 802.11a – 20 MHz 802.11b – 22 MHz 802.11g – 20 MHz 802.11n - 20 MHz or 40 MHz (two continuous 20 MHz bonded channels) - In 2.4 GHz, a 40 MHz channel uses much of the available bandwidth 802.11ac - 40 MHz for 802.11n stations - 80 MHz by default and is required for 802.11ac stations - 160 MHz optional (contiguous channels or non-contiguous bonded) Band Selection and Bandwidth Bluetooth High speed communication over short devices PAN (Personal Area Network) Connects our mobile devices - Smartphones - Tethering and file transfers - Headsets and headphones - Health Monitors - Automobile and phone integration - Smartwatches - External Speakers RFID (Radio-Frequency Identification) It’s everywhere, anything that needs to be tracked - Access Badges - Inventory / Assembly line tracking - Pet / Animal Identification Radar Technology - Radio energy transmitted to the tag - RF powers the tag, ID is transmitted back - Bidirectional communication - Some tag formats can be already active / powered NFC – Near Field Communication Two-way wireless communication Payment systems - Major credit cards - Online wallets Bootstrap for other wireless Builds on RFID, which is mostly one-way NFC helps with Bluetooth pairing Access token, identity “card” - Short range with encryption support Zigbee Internet of Things (IoT) networking Uses the ISM band (Industrial, Scientific, and Medical) Open standard – IEEE 802.15.4 PAN 900 MHz and 2.4 GHz frequencies in the US Alternative to WiFi and Bluetooth - Longer distances than Bluetooth - Less power consumption than WiFi WMN – Wireless Mesh Network of all Zigbee devices in your home - Meaning all devices connect through Zigbee can communicate through each other, and greatly expands size of network - Light switch communicates to light bulbs - Tell Amazon Echo to lock the door Z-Wave Proprietary home automation networking - Internet of Things (IoT) - Control lights, locks, garage doors, etc Also uses the ISM band (Industrial, Scientific, and Medical) - 900 MHz frequencies in the US - No conflicts with 802.11 Also WMN – Wireless Mesh Network - Nodes can hop through other nodes on the way to the destination Cellular Networks Mobile devices Separate land into “cells” “Cell” phones Antenna coverages a cell with certain frequencies Started with 2G Networks - GSM – Global System for Mobile Communications - CDMA – Code Division Multiple Access Poor data support as it was originally built for voice communication like phone calls - Originally used circuit-switching - Minor upgrades for some packet-switching 3G Technology 3rd Generation Introduced in 1998 Upgraded data connectivity over 2G - Incremental 3G updates improved speeds - Usually several megabits per second Bandwidth improvement allowed new functionality - GPS - Mobile television - Video on demand - Video conferencing 4G and LTE LTE – Long Term Evolution - A “4G” Technology - Converged standard (GSM and CDMA providers) - Based on GSM and EDGE – Enhanced Data Rates for GSM Evolution Standard supports download rates of 150 Mbit/s LTE-A (Advanced) - Standard supports download rates of 300 Mbit/s Moving to 5G Update to 4G - Rollout in late 2018 and 2019 - Worldwide launches in 2020 Significant performance improvements - At higher frequencies - May not be as significant at lower frequencies Technology updates - Additional frequencies - Improved data transmission methods 2.5 Network Services Web Server Respond to browser requests - Using standard web browsing protocols - HTML, HTML5 Web pages are stored on the server - Once your browser on your computer request for those pages from the server, those pages will be downloaded over the network to your browser - Static pages or built dynamically in real-time when a client is requesting them File Server Centralized storage of documents, spreadsheets, videos, pictures, and any other files Standard system of file management - For Windows it would be SMB (Server Message Block), for MacOS it would be AFP (Apple Filling Protocol) The front-end hides the protocol - Use the file manage available in their operating systems, and the protocols between their computer and server handles all these transactions Print Server Connect a printer to the network May be software in a computer Computer is connected to the printer May be built-in to the printer Provide printing services for all network devices Network adapter and software Uses standard printing protocols - For Windows SMB – Server Message Block - IPP – Internet Printing Protocol - LPD – Line Printer Daemon DHCP Server Dynamic Host Configuration Protocol Automatic IP address configuration Very common service - Available on most SOHO routers Enterprise DHCP will be redundant - Usually running on central servers DNS Server Domain Name System Convert names to IP addresses and vice versa Distributed naming system - The load is balanced across many different servers Usually managed by the ISP or enterprise IT department A critical resource Proxy Server An intermediate server - Client makes the request to the proxy - The proxy performs the actual request - The proxy provides results back to the client Useful features - Access control, caching, URL filtering, content scanning Mail Server Store your incoming mail Usually managed by the ISP or the enterprise IT department Send your outgoing mail A complex set of requirements Usually one of the most important services that require 24x7 support Authentication Server Login authentication to resources Almost always an enterprise service Centralized management and repository for all of the credentials Not required on a home network Usually run on a set of redundant servers - So that its always available - Extremely important service SIEM – Security Information and Event Management Logging of security events and information in one single database Security alerts Real-time information Log aggregation (consolidating) from all devices/servers - Usually includes advanced reporting features Long term storage Data correlation Link diverse data types and across a long period of time Forensic analysis - Gather details from all devices/servers after an event Syslog Standard for message logging Diverse systems, consolidated log Usually a central logging receiver, integrated into the SIEM - As long as the device can communicate its logs back through Syslog, you can consolidate everything in this central database (SIEM) Going to need huge amount of disk space as you are storing a lot of data over a long period of time Some Syslog consolidation tools and SIEMs will use WORM (Write Once Read Many) drive technology - Protect important security logs IDS (Intrusion Detection System) and IPS (Intrusion Prevention System) Intrusions - Exploits against operating systems, applications, etc - Buffer overflows, cross-site scripting, other vulnerabilities Detection vs. Prevention - Detection – Alarm or Alert - Prevention – Stop it before it gets into the network All-in-one Security Appliance Next-generation firewall / UTM – Unified Threat Management / Web Security Gateway URL Filter / Content Inspection Malware inspection Spam Filter CSU / DSU (Channel Service Unit/Data Service Unit) - A hardware device that converts digital data frames from the communications technology used on a local area network (LAN) into frames appropriate to a wide-area network (WAN) Router, Switch Firewall IDS/IPS Bandwidth Shaper QoS (Quality of Service) Endpoint Management Server Manage all devices from “one pane of glass” - Software installations - Driver installations - Software updates - Security patches - Remote troubleshooting Require an agent installed on all of the devices - Server sends the commands - Agent executes the commands Legacy and Embedded Systems Legacy systems - May also be “really important” - Learning old things can be just as important as learning the new things Embedded Systems - Purpose-built device - Not usual to have direct access to the operating system - Alarm system, door security, timecard systems 2.6 Network Configurations IP Addressing IPv4 is the primary protocol for everything we do IPv6 is slowly appearing IPv4 Addresses Internet Protocol version 4 – 32 bits - OSI Layer 3 address (Network) Since 1 byte is 8 bits, the maximum decimal value for each byte is 255 IPv6 Addresses Internet Protocol version 6 – 128 bits - 340 undecillion addresses, which means each individual can have a HUGE number of addresses assigned to them DNS will become very important so that we can refer to devices by name rather than IP addresses First 64 bits is generally the network prefix (/64) Last 64 bits is then the host network address Networking with IPv4 IP Address, E.G. 192.168.1.165 Every device needs a unique IP address Subnet mask, E.G. 255.255.255.0 - Used by the local device to determine what subnet it’s on - The subnet mask usually isn’t transmitted across the network Default gateway, E.G. 192.168.1.1 - This is the IP address of the router that allows you to communicate outside of your local subnet - The default gateway must be an IP address on the local subnet DNS Servers (Domain Name Services) We remember names Google.com, Youtube.com Internet routers or routers in general don’t know names - Routers only know IP addresses DNS has to translate between names and IP addresses You configure TWO DNS servers in your IP configuration in case one becomes unavailable - That’s how important it is DHCP (Dynamic Host Configuration Protocol) IPv4 address configuration used to be manual - IP address, subnet mask, default gateway, DNS servers, NTP servers, etc The bootstrap protocol (BOOTP) was released in October 1993 BOOTP didn’t automatically define everything - Some manual configurations were still required - BOOTP also didn’t know when an IP address might be available again DHCP – Dynamic Host Configuration Protocol - Released in 1997, and updated through the years - Provides automatic address / IP configuration for almost all devices Step 1: Discover There is a DHCP server on the local subnet as well as a DHCP server outside of the local subnet DHCP Relay (IP Helper) is configured on the router, so that if the router ever sees any requests for DHCP, to also send them to the DHCP server that’s outside When the client work station is first turned on, it does not have an IP address, so it will send a broadcast out to udp/67 over the network The broadcast will make its way to every device on the local subnet, and it will eventually reach the DHCP servers that have been configured on the network Step 2: Offer The DHCP servers will examine the broadcast If they have an IP address that’s available, they will make an offer to the client workstation through a broadcast to udp/68 The broadcasts from both the DHCP servers will be seen by the client workstation Step 3: Request When multiple offers are made to the device, the device usually chooses the first offer that was received Now that it knows that an IP address is available, the client workstation will send a broadcast over udp/67 to request that IP address Step 4: Acknowledge Once the DHCP server receives the address, it will broadcast a formal acknowledgement to that address to the client workstation through udp/68 At this point, the client workstation can configure itself with that IP address Turning dynamic into static DHCP assigns an IP address from the first available from a large pool of addresses You may not want your IP address to change IP address will occasionally change Server, Printer, or personal preference Disable DHCP on the device - Configure the IP address information manually - Requires additional administration Easier way is to configure an IP Reservation on the DHCP server - Associate a specific MAC address with an IP address - If you need to make changes, just go on the DHCP server, and the change will be implemented across all of the devices configured APIPA – Automatic Private IP Addressing If you turn on your computer and you don’t receive a response from a DHCP server, you might still be able to communicate with other devices within your local subnet It is a link-local address No forwarding by routers Automatically assigned by the operating system - Before it puts that address onto your workstation, it sends an ARP (Address Resolution Protocol) to the local network to ensure nobody else is using the IP address that it wants to assign to your workstation IETF has reserved 169.254.01 through 169.254.255.254 - First and last 256 addresses are reserved - Functional block of 169.254.1.0 through 169.254.254.255 Example of a APIPA configured on a workstation: IPv6 Link-local Addresses A non-routable local network address Will only work on the local subnet, same as IPv4 link-local addresses Required on every IPv6-enabled interface - You may see many IPv6 addresses per interface o A link-local address, and an address that allows you to communicate outside of your local subnet fe80::/10 with only one subnet allocated (all zeros) - Effectively becomes fe80::/64 o Zeros in the first 64 bits, and the last 64 bits are assigned as node addresses (host addresses) The last 64 bits are usually created with a modified EUI-64 (Extended Unique Identifier) - Based on the MAC address, so that there is some uniqueness to the linklocal address SSL VPN – Secure Sockets Layer VPN Uses common SSL/TLS protocol (tcp/443) - TLS – Transport Layer Security, an improved version of SSL - Avoid running into most firewall issues No big VPN clients (for end-users) - Usually remote access communication, and create a secure tunnel between end-user’s device and the corporate network Simply assign authentication credentials to a user, and they can use the same username and password they always use to gain access to the SSL VPN No requirement for digital certificates or shared passwords (like IPSec) Can be run from a browser or from a (usually light) VPN client that is built into your operating system - Across many operating systems Client-to-Site VPNs Also called “remote access VPN” Requires software on the user device - May be built-in to existing operating system Decrypted Decrypted Encrypted You can simply start the SSL VPN software on your laptop, and it creates this encrypted tunnel back to your VPN concentrator at the corporate facility - If anyone was to capture any of the traffic between your remote workstation and the VPN concentrator, all they would see is encrypted information The VPN concentrator is then responsible for decrypting that information and sending it into the corporate network When this information is sent back to your remote workstation, it is encrypted by the VPN concentrator, and decrypted by your laptop LANs – Local Area Network A group of devices in the same broadcast domain 1 2 We often maintain the separation of the different local area networks for security reasons and to maintain the efficiency of the network - Means that we need a separate switch every time we want to have a separate broadcast domain VLAN – Virtual LANs To simplify the separate broadcast domains, we create a virtual LAN A group of devices in the same broadcast domain Separated logically instead of physically All of the devices on the red network can only see and communicate with the other devices on the red network Same with devices in the blue network We can configure a single switch to act and operate as if its multiple switches - Simplifies the administration - Save cost Configuring VLANs All devices connected in the red ports can communicate to each other on VLAN 1 Same with blue ports (VLAN 2) and green ports (VLAN 3) None of the devices can communicate across to a different VLAN 2.7 Internet Connections Cable Modem Broadband - Transmission across multiple frequencies - Different traffic types Data on the “cable” network - DOCSIS – Data Over Cable Service Interface Specification - Coaxial Cabling, shared bandwidth High-speed networking - 4 Mbits/s through 250Mbits/s are common - Gigabit speeds are possible Multiple services - Data for our internet connection, voice for telephone communication, and video for cable television DSL Modem ADSL – Asymmetric Digital Subscriber Line - Uses telephone lines instead of cable for cable television Twisted-pair copper cabling, dedicated bandwidth Download speed is faster than the upload speed (Asymmetric) - ~10,000 foot distance limitation from the telephone company’s central office (CO) - 52 Mbit/s downstream, 16 Mbit/s upstream are common - Faster speeds may be possible if closer to CO Dialup Network with voice telephone lines Analog lines with limited frequency response 56 kbit/s modems - Compression up to 320 kbit/s Relative slow throughput and difficult to scale Legacy systems, network utility - May be difficult to find a modem nowadays Fiber Optics Fiber optics to the home Converged services High speed networking Voice, Video, Data Enhanced features - Hundreds of HD channels - 1 Gbit/s Internet access - 1 Terabyte of cloud storage - 2 Terabyte DVR Satellite Networking Communication to a satellite - Non-terrestrial communication High cost relative to terrestrial networking 50 Mbit/s downstream, 3 Mbit/s upstream are common - Allow you to connect from remote sites or difficult-to-network sites High latency 250 ms upstream, 250 ms downstream High frequencies – 2 GHz - Line of sight, there is rain fade (no internet connectivity if there is heavy thunderstorm) ISDN – Integrated Services Digital Network BRI – Basic Rate Interface (2B + D) - Two 64 kbit/s bearer (B) channels (sending data over ISDN connections) - One 16 kbit/s signaling (D) channel (sets up or tear down the connection, and sends management information) PRI – Primary Rate Interface - Delivered over a T1 or E1 o T1 – 23B + D o E1 – 30B + D + alarm channel - Commonly used as connectivity from the PSTN (public switched telephone network) to large phone systems (PBX – Private Branch Exchange) Cellular Networks Mobile devices Separate land into “cells” Antenna coverages a cell with certain frequencies Tethering “Cell” phones Turn your phone into a wireless router through wire to laptop Mobile hotspot - Standalone devices - Use your phone for other things Line-of-sight Wireless Internet Services Line-of-sight - Visual path between antennas - High frequencies Common in metropolitan areas as it covers a wide geographical area - Cover many homes simultaneously WiMAX networking - Worldwide Interoperability for Microwave Access - Wireless high-speed internet access Also have options for non-line-of-sight - Lower frequencies, slower speeds LAN – Local Area Network Local is relative Same room, building or a group of buildings High-speed connectivity Ethernet and 802.11 wireless - Any slower and it isn’t “local” WAN – Wide Area Network Spanning the globe Generally connects LANs across a distance that is very far away - Generally much slower than LAN Many different WAN technologies - Point-to-point serial, MPLS (Multi-Protocol Label Switching), etc - Terrestrial and non-terrestrial PAN – Personal Area Network Your own private network Bluetooth, IR, NFC Automobile - Audio output, integrated with phone Wireless headset with mobile phone Health - Workout telemetry, daily reports MAN – Metropolitan Area Network A network in your city - Larger than a LAN, often smaller than a WAN Historically MAN-specific topologies - Everyone is moving to Metro Ethernet o Local network provider is going to hand off an ethernet connection, and you simply plug into that ethernet port Common to see government ownership - As they “own” the right-of-way” WMN – Wireless Mesh Network All devices connect together, like IoT (Internet of Things) A mesh “cloud” Self-form Self-heal Connects to each other automatically Reacts automatically to changes Many different network technologies - 802.11, Zigbee, Z-wave, etc 2.8 Network Tools Cable Crimpers “Pinch” the connecter onto a wire Connect the modular connectors to the ethernet cable Coaxial, twisted pair, fiber The final step of the process Metal prongs are pushed through the insulation so that you have copper to copper connectivity - The plug is also permanently pressed onto the cable sheath Modular Connectors A good crimp Crimping best-practices - A good pair of electrician scissors / cable snips - A good wire stripper Make sure you use the correct modular connectors - Differences between wire types Multimeters AC voltage Check wall outlet voltage DC voltage - PC power supply output voltages - CMOS battery power Continuity tests - Cable connectivity - Fuse status - Wire mapping Tone Generator Where does that wire go? Tone generator Follow the tone Puts an analog sound on the wire Inductive probe - Doesn’t need to touch the copper, hear through a small speaker Easy wire tracing Even in complex environments Connect the tone generator to the wire - Modular jack - Coax - Punch down connectors Use the probe to locate the sound - The two-tone sound is easy to find Cable Testers Relatively simple Can identify missing pins Continuity test Or crossed wires Only tells us if we have wired it properly - Not used for frequency testing o Crosstalk, signal loss, etc Loopback Plugs Useful for testing physical ports - Or for fooling your applications that is expecting to have an ethernet connection available, even if you are not directly connected to a live ethernet network - As they are used for looping back traffic from one interface back into the same interface Serial / RS-232 (9 pin / 25 pin) Separate loopback plugs for different network connections Ethernet, T1, Fiber These are not cross-over cables - They cannot be used to connect different devices with each other Punch-down Tools Punch-down blocks are intermediate section between a user’s workstation and the networking equipment that might be in a closet or server room “Punch” a wire into a wiring block 66 or 110 block Can be tedious - As every wire must be individually punched Trims the wires during the punch Very efficient process Punch-down best practices - Organization is key as there is lots of wires Cable management Maintain your cable twists as close as possible to the blocks Your category 6A cables will thank you later Document everything - Written documentation, Tags, Graffiti Wi-Fi Analyzer Wireless networks are incredibly easy to monitor Everyone “hears” everything Purpose-built hardware or software installed on your device - Specializes in 802.11 analysis Identify errors and interference - See all of the signal strengths and frequencies that are in use in your area or network, in order to identify errors or interference - Manage how to configure your wireless network to perform optimally - Validate antenna location and installation 3. Hardware 3.1 Cables and Adapters The Importance of Cables Incredibly important fundamental to network communication Usually only get one good opportunity at building your cable infrastructure Even vast majority of wireless communication uses cables Twisted Pair Copper Cabling Balanced pair operation - Two wires with equal and opposite signals - Transmit +, Transmit - / Receive +, Receive – The twist keeps a single wire constantly moving away from the interference Once the signal reaches the end of the wires, the opposite signals are compared to each other to reconstruct anything that may have been corrupted by this interference Pairs in the same cable have different twist rates - This will also help in making sure that traffic is able to get through the network even when there is interference Network Cabling Standards EIA – Electronic Industries Alliance - Alliance of trade associations, develops standards for the industry - Standards start with RS-# (Recommended Standards) or EIA-# TIA – Telecommunications Industry Association - Standards, Market analysis, Trade shows, Government affairs, etc - ANSI / TIA / EIA-568 – Commercial Building Telecommunications Cabling Standard o Always used when laying cabling infrastructure in buildings International ISO / IEC 11801 Cabling Standards - Define classes of networking standards Copper Cable Categories No Plenum Plenum Plenum Space - Building air circulation - Heating and air conditioning system Concerns in the case of a fire May be network cables and water pipes running in the plenum Smoke and toxic fumes if there is network cables running Worst-case planning - Proper network cabling if it is running through a plenum Plenum-Rated Cable Traditional cable jacket - PVC – Polyvinyl Chloride o If it catches on fire, the fumes are toxic Fire-rated cable jacket - FEP – Fluorinated Ethylene Polymer - Low-Smoke PVC Plenum-rated cable may not be as flexible May not have the same bend radius Worse-case planning - Important concerns for any structure Unshielded and Shielded Cables UTP – Unshielded Twisted Pair - No additional shielding - The most common twisted pair cabling STP – Shielded Twisted Pair - Additional shielding protects against interference Extra pair of grounding wire - Shield each pair and/or the overall cable - Requires the cables to be grounded Abbreviations: - U = Unshielded - S = Braided Shielding (shield around each individual pairs of wire) - F = Foil Shielding (Overall cable) / (individual pairs) TP - F/UTP = Foil around the cable and no shielding around the pairs - S/FTP = Braided shielding around the entire cable and foil around the pairs T568A and T568B Termination Pin assignments from EIA/TIA-568-B standard Eight conductor 100-ohm balanced twisted-pair cabling T568A and T568B are different pin assignments for 8P8C (8 position, 8 conductor) connectors (also known as RJ45) Many organizations traditionally use 568B Assign the T568A pin-out to horizontal cabling (same floor of a building) Difficult to change in mid-stream You can’t terminate one side of the cable with 568A and the other with 568B - Will run into problems, such as not being able to run Gigabit speeds and cable troubleshooting issues Coaxial Cables Two or more forms share a common axis RG-6 used in television / digital cables (in cable modems) And high-speed internet over cable RG-59 used as patch cables from the cable modem to other devices - Not designed for long distances Optical Fiber Communication Transmission by light No RF (Radio Frequency) signal The visible spectrum Very difficult to monitor or tap Signal slow to degrade - Transmission over long distances Immune to radio or electrical interference - There’s no RF The ferrule is made of ceramic, and help to protect the fiber core when connecting and disconnecting from network equipment Multimode Fiber The optic fiber you would put between two devices will either be multimode fiber or single-mode fiber Multimode fiber means when the light is going into the fiber core itself, it is going to bounce around into multiple modes, and when it comes out on the other side you will see the light is in those different modes Short-range communication - 2 km for 100 Mbit/s - 550 m for 10 Gbit/s Inexpensive light source - Usage of LED to send the light signal Single-mode Fiber Long-range communication Over 80 km without additional processing Expensive light source - Laser beams VGA – Video Graphics Array DB-15 connector (15 pins) Blue colour More accurately called DE-15 PC System Design Guide Analog signal - Image degrades after 5 to 10 meters HDMI – High-Definition Multimedia Interface Video and Audio stream - All digital - About 20 meters distance before losing too much signal 19-pin (Type A) connector Proprietary connector miniHDMI - Type C connector - Designed for smaller devices DisplayPort VESA (Video Electronics Standards Association) standard Data is sent in packetized form Royalty-free standard Like Ethernet and PCI express Compatible with HDMI and DVI - Use passive unpowered adapter to be able to convert between DisplayPort and HDMI DVI – Digital Visual Interface Single and dual link - Single link: 3.7 Gbps (HDTV at 60 fps) - Dual link: 7.4 Gbps (HDTV at 85 fps) - Analog Signals - Digital Signals - Integrated - Digital and analog in the same connector DVI-A DVI-D DVI-I Lightning Cables Apple proprietary - 8-pin digital signals Some advantages over Micro-USB - Higher power output, can be inserted either way, more durable Thunderbolt Used to connect a peripheral device such as storage device or video display to your computer High-speed serial connector - Data and power on the same cable - Based on Mini DisplayPort (MDP) standard Thunderbolt v1 - Two channels - 10 Gbit/s per channel - 20 Gbit/s total throughput - Mini DisplayPort connector Thunderbolt v2 - 20 Gbit/s aggregated channels - Mini DisplayPort connector Thunderbolt v3 - 40 Gbit/s aggregated throughput - USB-C connector Maximum 3 meters for copper - Up to 60 meters with optical - Allows you to Daisy-chain up to 6 devices USB – Universal Serial Bus Simplify connections - Printers, storage devices, keyboard, mouse, etc USB 1.1 - Low speed: 1.5 Mbit/s, 3 meters - Full speed: 12 Mbit/s, 5 meters USB 2.0 - 480 Mbit/s, 5 meters USB 3.0 - SuperSpeed - 5 Gbit/s, ~ 3 meters o Standard does not specify a cable length USB 1.1 / 2.0 connectors: USB 3.0 connectors: USB 3.1 - Released July 2013 - SuperSpeed+ - Type-A and USB-C connector - 10 Gbit/s (twice the rate of USB 3.0) USB 3.2 - Released September 2017 - New SuperSpeed+ modes over USB-C - 10 Gbit/s and 20 Gbit/s - USB-C can replace all of the previous USB connectors USB-C o USB-C can be plugged in either way, so its not annoying compared to connect the USB-A - USB-C isn’t necessarily USB 3.1 o The cable must support the function: o USB 3.1 speeds, power delivery of > 7.5 watts, alternate mode (additional data wires) DB-9 Serial Cable Connector D-subminiature or D-sub Different sizes, A through E Commonly used to send serial data over an RS-232 connection - Recommended Standard 232 - An industry standard since 1969 Serial communications standard - Built for modem communication - Used for modems, printers, mice, networking Also commonly used as a configuration port - Serial console interface SATA – Serial Advanced Technology Attachment SATA Revision 1.0 SATA 1.5 Gbit/s, 1 meter SATA Revision 2.0 - SATA 3 Gbit/s, 1 meter SATA Revision 3.0 SATA 6 Gbit/s, 1 meter SATA Revision 3.2 - SATA 16 Gbit/s, 1 meter The PATA Standard For older / Legacy type of storage Parallel AT Attachment, Parallel ATA, ATA An evolutionary process, and was created around 1999 Originally called IDE – Integrated Drive Electronics - A Western Digital invention - 2nd generation called EIDE – Enhanced IDE The evolution - Promised faster speeds (from 16 MB/s through 133 MB/s) - Additional devices (CD-ROM drives, etc) Now called PATA – Parallel ATA Additional wires in the 80-wire cable is used for grounding inside of the cable to reduce the amount of crosstalk, and improve throughput Comparison of PATA and SATA Cabling: SATA cable takes up much less room inside of a computer case, and allow for more airflow in the computer case thus having better cooling The SCSI Standard SCSI – Small Computer Systems Interface - Not really “small” any longer - When it was introduced, there was no USB Originally designed to string many peripherals together onto a single cable/controller (hard drives, optical drives, scanners all along the same SCSI bus) Up to 16 devices in a SCSI “chain” Many different formats - Fast SCSI, Ultra SCSI, Ultra-Wide SCSI, Ultra2 SCSI, Ultra3 SCSI, Ultra320 SCSI, Ultra-640 SCSI, iSCSI (SCSI over IP) Parallel and Serial options available Not just for hard drives - Scanners, tape drives, CD-ROM drives Many devices on a single bus 8 on a narrow bus, 16 on a wide bus Very intelligent interface functionality - Much of the difficult configuration work that administrators have to do is done between the SCSI devices Industry longevity - Well supported in the enterprise - A standard drive for virtual systems Every SCSI device on a single bus is assigned a separate ID number - Logical unit (LUN) numbers are defined within each SCSI ID SCSI ID 0 (SCSI controller), ID 2 (Hard Drive), ID 3 (CD-ROM) Separate drives in a storage array or virtual machine The signal at the “end” of a physical SCSI bus is terminated - Can be internal to the device or a separate termination device Modern data centres probably using a newer SCSI device called SAS – Serial attached SCSI, that have no jumpers, terminators, or settings An external storage drive that connects with SCSI: Daisy Chaining Legacy SCSI drive: SAS – Serial Attached SCSI Move from parallel to serial - Increased throughput, and added flexibility - More expensive than SATA, generally used for servers or in processingheavy computer workstations Point-to-point connection The bus has two devices on it The control and management of SCSI No more daisy chains No termination required Similar to the move from PATA to SATA But have the high speed of a serial connection 2.5” SAS drive: High-density internal SAS connector: Drive arrays normally used in enterprise settings: 24 drives on the top array, and 24 drives on the bottom array Adapters and Converters Convert between different connectors Convert from one format to another They must be electrically compatible You need Ethernet but you only have USB A good temporary fix - Or a good permanent one DVI to HDMI DVI-D and HDMI are electrically compatible - HDMI is backward-compatible with DVI-D - No signal conversion required - No loss of video quality DVI-A to VGA DVI-A includes analog signals - Backward compatible with VGA - Only 640 x 480 resolution is officially supported May only need an adapter Analog to analog VGA to DVI-D will need a converter (a power device that will perform a conversion of those signals) - Check your interface specifications USB to Ethernet Some newer laptops don’t have a wired Ethernet interface Convert USB to Ethernet 3.2 Connectors RJ11 Connector 6P2C – 6 position, 2 conductor RJ14 uses 6P4C for dual-line use Telephone connection RJ45 Connector 8P8C – 8 position, 8 conductor - Modular connector - Wired Ethernet connection Similar in shape to an RJ48C - 8P4C, used with T1/WAN data lines RS-232 Connector Recommended Standard 232 An industry standard since 1969 Serial communications standard - Built for modem communication - Used for modems, printers, mice, networking Also commonly used as a configuration port - Serial console interface BNC Connector Bayonet Neill-Concelman Common type of coaxial cable connector - Paul Neill (Bell Labs) and Carl Concelman (Amphenol) DS3 WAN links Rigid and bulky - Can be difficult to work with F-connector Cable television Cable modem Coaxial RG-6 or RG-59 cable - Threaded connector (must screw in) USB 1.1 / 2.0 connectors USB 3.0 connectors USB-C Connector Lightning Connector Apple proprietary - 8-pin digital signals Some advantages over Micro-USB - Higher power output - Can be inserted either way - More durable SCSI Interfaces 2.5” SAS drive (Serial Attached SCSI) High-density internal SAS connector eSata Connector External SATA connection Molex Connector 4-pin peripheral power connector - Molex Connector Company - AMP MATE-N-LOK - Provides +12 V and +5 V For older peripherals or maybe for fans Power for many devices in the computer case - Older Storage devices - Optical drives - Fans and other peripherals Power Supply The power for Molex is usually provided directly from the power supply Bundle of cables for connection to the motherboard, including the 4-pin Molex connectors 3.3 Memory What is memory? RAM – Random Access Memory is the most common RAM is not referring to hard drive or SSD storage It’s not the only kind of memory On a drive, data is stored permanently Data and programs can only be used when moved to RAM - RAM is essentially short-term memory where data is stored as the processor needs it - Anytime you play a game from your computer’s hard drive or stream a movie from the Internet, all of the data that your computer’s processor needs to play the game or watch the movie is stored in RAM. This is so that your processor can get to it quickly - Once you’re done playing your game or watching your movie and you close it down, the processor doesn’t need that data anymore, so it replaces it with the next task you give it RAM Slots Memory types have changed throughout the years - Driven by standardization and technology One of the most important components of your computer As it determines the overall performance Every motherboard is different - Check the motherboard manual to know the specifications of RAM supported DIMM – Dual Inline Memory Module Electrical contacts are different on each side 64 bit data width - Means we are able to transfer data from these memory modules in chunks of 64 bits at a time SO-DIMM – Small Outline Dual In-line Memory Module About half the width as a DIMM Usually in a laptop and mobile devices DDR2, DDR3, and DDR4 SDRAM DRAM – Dynamic Random Access Memory The memory on the DIMM Dynamic - Needs constant refreshing - Without refreshing, the data in memory disappears Random Access - Any storage location can be accessed directly - Unlike magnetic tape SDRAM – Synchronous DRAM Found in today’s desktops and computers SDRAM is synchronous with the common system clock - Queue up one process while waiting for another - Classic DRAM didn’t wait for a clock signal SDR (Single Data Rate) vs DDR (Double Data Rate) DDR2 SDRAM Faster speeds - Twice as fast as DDR - Maximum of 8 GB per DIMM (compared to 512 MB for DDR) Not backwards and forward compatible - DDR2 won’t work in DDR, DDR3, or DDR4 slots DDR3 SDRAM Twice the data rate of DDR2 Larger chip capacities – Maximum 16GB per DIMM Not backwards compatible DDR4 SDRAM Speed increases over DDR3 - Faster frequencies - Maximum 64 GB per DIMM Not backwards compatible DIMM Size Comparison Multi-channel Memory Dual-channel, triple-channel, or quad-channel Memory combinations should match - Exact matches are the best, as they provide the best performance Memory That Checks Itself Most of the memory that we’re using on our desktop computers doesn’t provide any type of error checking or error correction Used on critical computer systems VM servers, Database servers, any servers Parity Memory - Adds an additional parity bit - Won’t always detect an error - Can’t correct an error ECC Memory (Error Correcting Code Memory) - Detects errors and corrects on the fly - Not all systems use ECC - It looks the same as non-ECC memory Parity Even parity - The parity bit makes the total bits an even number Valid or error? - Even parity byte - Now that these parity bits have been added to this memory, and the transactions have occurred in the RAM, it is now ready to write this information back to the storage drive In the second line, it is not an even byte, that means something must have gone wrong, and that particular byte is corrupted. The parity memory will recognise that particular byte as invalid 3.4 Storage Optical Formats Small bumps on the discs that is read with a laser beam CD-ROM (Compact Disc ROM) Microscopic binary storage 700 MB capacity DVD-ROM (Digital Versatile Disc) - 4.7 GB for single-layer - 8.5 GB for dual-layer Blu-ray Disc - 25 GB for single-layer - 50 GB for dual-layer Writing to optical media “Burners” don’t create bumps in the discs - They darken certain areas of the disc that have photosensitive dye in them Compact Disc-ReWritable (CD-RW) DVD Read and ReWritable (DVD-R/RW) - And Dual Layer (DVD-R DL) Blu-ray Disc Recordable (BD-R) Blu-ray Disc Recordable Erasable (BD-RE) SSD – Solid-State Drives Non-volatile memory Very fast performance No moving parts No spinning drive delays SSD commonly seen installed into a PCI Express slot, normally in servers 2.5 Inch SATA Interface SSD Normally used in a desktop or laptop M.2 SSD Interface Smaller storage device - As fast or faster than SATA - No SATA data or power cables PCI Express bus connection 4 GB/s throughput or faster Different connector types - Needs to be compatible with the slot key - B key, M key, or B and M key, some M.2 drive supports both B key - Maximum of PCIe x 2 lanes - Maximum of PCIe x 4 lanes M key Hard Disk Drives Non-volatile magnetic storage Rapidly rotating platters Random-access - Retrieve data from any part of the drive at any time Moving parts - Spinning platters, moving actuator arm - Mechanical components limit the access speed - Mechanical components can also break Hybrid Drives SSHD – Solid State Hybrid Drive - Both a spinning drive and SSD in a single device SSD caches the slower spinning hard drive data - Write to the SSD cache very quickly, and in the background, the cache is writing to the hard drive as you’re doing other things Increases speed without the cost of an SSD-only system Looks like a normal hard drive or SSD - Same form factor Drive Size Comparison USB Flash Drives Flash Memory - EEPROM (Electrically Erasable Programmable Read-Only Memory) - Non-volatile memory - No power required to retain data Limited number of writes Can still read data Not designed for archival storage - Easy to lose or damage - Always have a backup Flash Memory Data Redundancy Hard drives store huge amounts of data Hard drives are moving components Important data They will eventually break You can prepare for that by using an array of drives and sharing the information over that array RAID – Redundant Array of Independent Disks They are also inexpensive disks Different RAID levels - Some very redundant and provide us with access to our data even if a drive happens to fail, and there are some that provides no redundancy RAID 0 – Striping RAID 1 – Mirroring RAID 5 – Striping with Parity Nested RAID – RAID 1 + 0 (aka RAID 10) - A stripe of mirrors Software RAID vs Hardware RAID Software-based RAID - A feature of the operating system - Doesn’t require any special hardware - Usually lower performance than hardware-based Hardware-based RAID - A feature of the hard drive controller - Configured outside of the OS o Usually invisible to the OS - High performance, designed for speeds Hot Swappable Drives Add and remove while the system is running Uses a drive chassis The connection is “hot” Where you can put 2 or more drives Easy to repair, replace a drive while the system is running - Combine with RAID for 100% uptime RAID 0 – Stripping File blocks are split between 2 or more physical drives High performance Data written quickly No redundancy - A drive failure breaks the array - RAID 0 is zero redundancy - If one of the drive fails, you lose access to all of your data RAID 1 – Mirroring File blocks are duplicated between 2 or more physical drives High disk space utilization - Every file is duplicated - Required disk space is doubled High redundancy - Drive failure does not affect data availability RAID 5 – Striping with Parity File blocks are striped - Along with a parity block - Requires at least 3 disks Efficient use of disk space - Files aren’t duplicated, but space is still used for parity High redundancy - Data is available after drive failure o Data is reconstructed using the parity - Parity calculation may affect performance RAID 10 (1+0) – A Stripe of Mirrors The speed of striping and the redundancy of mirroring - The best of both worlds, requires at least 4 drives 3.5 Motherboards, CPUs, and Add-on Cards Motherboard Form Factors Physical size - Basic layout - Room for small changes - Standard connectors Power Airflow - Case sizing Increasingly important Focus on which motherboard would be the best choice for a scenario - ATX, microATX, ITX, and mini-ITX ATX (Advanced Technology Extended) Form Factor Standardized by Intel in 1995 - Seen many updates over the years Motherboard Power - Original ATX motherboard has 20 pin connectors - Newer ATX motherboard has 24 pin connectors, and additional 4/8 pin connector for CPU power ATX motherboards are still manufactured today ATX is still the popular standard for personal computers MicroATX (uATX) Form Factor Smaller than an ATX motherboard Limited expansion slot Backwards compatibility (ATX) - Same power connectors - Same mounting points Also very popular form factor Still manufactured today ITX (Information Technology Extended) Form Factor A series of low-power motherboards Mini-ITX is screw-compatible with ATX and microATX Developed by VIA Technologies in 2001 Fits almost any case Small form factor uses - Single-purpose computing - i.e. streaming media A Computer Bus Communication path Internal PC growth A city of technology Independent pathway System expansion - Additional capabilities The Expansion Bus Older expansion slots that supported parallel communication allowed us to send information across the bus - The wider the bus, allowed us to send more information - “width” in bits Newer serial bus uses total amount of bandwidth we’re able to communicate across the bus Clock speed of the bus - The expansion bus gets its own clock - 1 MHz (megahertz) = 1 million cycles per second - 1 GHz = 1000 MHz = 1 billion cycles per second Clock speed does not necessarily equal transfer rate - DDR3 SDRAM can transfer 64 times the memory clock speed Conventional PCI (Peripheral Component Interconnect) Created in 1994 A common expansion interfaces - 32-bit and 64-bit bus width - Parallel communication Throughput varies by bus version - 133 MB/s (32-bit at 33 MHz) - 266 MB/s (32-bit at 66 MHz or 64-bit at 33 MHz) - 533 MB/s (640bit at 66 MHz) 32-bit PCI Parallel Bus 64-bit PCI Parallel Bus PCI 32-bit Expansion Card PCI 64-bit Expansion Card PCI Express (PCIe) Replaced PCI, PCI-X, and AGP (Accelerated Graphics Port) Communicates serially - Unidirectional serial “lanes” - Not all devices share these “lanes”, so slower devices don’t slow down all devices One, two, four, eight, sixteen, or thirty-two full duplex lanes - x1, x2, x4, x8, x16, x32 - “x” is pronounced “by” (“by 4”, “by 16”) PCI Express Serial Communication PCI Express Throughput Different versions of PCIe Improvement in speed with each iteration Per-lane throughput in each direction - v.1x: 250 MB/s - v.2x: 500 MB/s - v.3.0: ~ 1 GB/s - v.4.0: ~2 GB/s - v.5.0: ~ 4 GB/s Data Centre Servers Because the interface card is taller than the server rack, so we need a Riser card so that we can mount the interface card horizontally Riser Card CPU Sockets (Central Processing Unit) Motherboards are matched with CPUs CPU socket is usually the largest connector on the board CPUs have specific socket requirements And usually central to everything Not easily upgradable - And often not an option ZIF Socket (Zero Insertion Force) PGA – Pin Grid Array LGA – Land Grid Array Reverse of the PGA Pins are on the motherboard No pin to damage on the CPU - Easier to damage motherboard LGA Processor Storage Drive Interfaces – SATA Storage Drive Interfaces – SATA and PATA Computer Case Various front-panel connections - Not directly connected to the motherboard - So you must connect it directly to the motherboard Most front panel connectors are labelled Internal USB Connector USB on the motherboard Integrated – part of the motherboard on the back Internal case connection BIOS – Basic Input/Output System The software used to start your computer - The firmware - System BIOS, or ROM BIOS (Stored on ROM for older computers) - Newer computer systems store BIOS on flash memory, so we can upgrade the BIOS using an application instead of removing and installing chips Initializes the CPU and Memory - Build the workspace POST – Power-On Self-Test This process will look for a CPU, Memory, Display, Keyboard, etc If all of the hardware passes the diagnostics in POST - It will start looking for a boot loader on a storage device to load the operating system The flash memory on the motherboard that contains the BIOS software It has a Main BIOS on the right, and a Backup BIOS on the right Easily allows upgrade to the BIOS, and allow users to be able to switch back and forth between different BIOS versions Legacy BIOS The original / traditional BIOS Been around for more than 25 years Older operating systems talked to hardware through the BIOS Instead of accessing hardware directly Limited hardware support - No drivers for modern network, video, and storage devices UEFI BIOS (Unified Extensible Firmware Interface) Based on Intel’s EFI (Extensible Firmware Interface) A defined standard Implemented by the manufacturers Designed to replace the legacy BIOS - For modern computers - Graphical and text-based UEFI Advantages Boot from large (>2.2 TB) GUID (Globally Unique Identifier) Partition Table (GPT) disks - Also supports FAT (File Allocation Table) formatted drives, and removable media (USB flash drives) Includes a pre-boot environment - This isn’t an operating system (OS) - Has its own shell, drivers, and applications - Browse the internet, backup a storage drive - Remote diagnostics, even without an OS Non-Volatile BIOS Memory Store the BIOS configuration Your settings CMOS – Complementary Metal-Oxide Semiconductor - A type of memory on older BIOS - Allowed us to write and change information on the CMOS, and there was a battery on the motherboard to constantly refresh the information so that we don’t lose our configurations Usually flash memory these days - Easily stored and accessed The “CMOS” Battery Not needed for today’s flash-based storage - Maintains older BIOS configurations - May only be used to maintain date/time A bad battery will require a BIOS configuration or date/time configuration on every boot On older systems, can reset the BIOS configuration by removing the battery Newer computers use a jumper Launching BIOS Del, F1, F2, Ctrl-S, Ctrl-Alt-S Play around the BIOS settings in a virtual environment - Hyper-V (windows 8/10) - 3rd party virtualization – VMware Workstation Player Fast Startup Windows 8 and Windows 10 - Doesn’t actually shut down all the way - Starts up very quickly Starts up so quickly, you can’t open the BIOS configuration Disable fast startup in the Control Panel / Power Options Some motherboards have a separate process - Hold F2, then press the power button Configure Component Information RAM View and configure memory settings Hard Drive / SSD - Drive settings - Boot order Optical Drive (CD-ROM / DVD-ROM) - Enable / Disable CPU types Built-in Diagnostics Part of the BIOS Run from the BIOS menu Always available No additional media or software required Focused on hardware checks - Doesn’t touch the operating system (OS) Important Tips Have a backup of your BIOS configuration - Makes notes or take a picture - Some BIOS will have a backup and restore process within the BIOS itself Don’t make a change unless you’re certain of the settings BIOS Passwords BIOS password / User Password - Systems won’t start - Need the password to start the operating system Supervisor Password - Restrict BIOS changes - Must use supervisor password to change any BIOS configuration Full Disk Encryption (FDE) Everything that is written onto a disk, including the operating system, is encrypted In Windows, this is called BitLocker disk encryption Not just individual files BIOS integrates with TPM TPM – Trusted Platform Module - Can be added to many motherboards - Built-in to some systems - Adds advanced cryptographic functions LoJack for Laptops Originally called CompuTrace - Name licensed from the vehicle recovery service (LoJack) Allows you to track where your laptop is Built into the BIOS - Software installed into the OS - Reinstalls itself if removed or new storage drive installed “Phone home” function Provides location information Theft Mode - Remotely lock the laptop and/or delete files - Force a startup password Secure Boot Malicious software can “own” your system Malicious drivers or OS software Secure boot - Part of the UEFI specification Digitally sign known-good software - Cryptographically secure - It looks at the core operating system files, and checks to see if there is a digital signature for those files - If the digital signature matches the files that are on your hard drive, then the system continues to boot - If the core operating system files have been modified, the digital signatures will fail, and software won’t run without the proper signature Support in many different operating systems - Windows and Linux support Firmware Upgrades Firmware - Non-volatile memory and software - Older-style ROMs - Newer-style flash memory Computer BIOS, video adapter firmware, game console, etc. - Improve performance, fix bugs Not usually part of a normal maintenance process - Upgrade for a specific reason Identify Current BIOS Version May appear when system starts Easier to look in System Information (msinfo32) Version and Date details Compare the current to the existing version on the manufacturer’s website Can be difficult to catch An upgrade may not be available If possible, get a copy of the current version from the manufacturer’s website for a backup Before Upgrading Read the documentation on the manufacturer’s website - Some BIOS updates are bland - Others are full of new features - Check for OS prerequisites Locate a reliable power source - Laptop: Connect to AC power and have a full battery - Desktop: Use a UPS (Uninterruptible Power Supply), if possible Run the Upgrade Program Really-old BIOS upgrades may require a boot disk Most modern upgrades run as an executable - Close all of your other applications before running - May also run in the BIOS from a flash drive Most upgrade apps will check for prerequisites Floppy or optical media But don’t rely on this Requires a reboot, so save your important documents Other Options for Upgrading Newer options may be available - Modern motherboards have advantages Multiple BIOS versions - Two separate BIOS versions - Easily switch between them Upgrade from a USB flash drive - Computer may not even need to be powered on CPU Processor Cores Dual-core / Quad-core / Octa-core / Multi-core And more all the time Multiple cores - Each core has its own CPU and cache - The entire chip may have a shared cache CPU Cache Super fast memory - There’s not much of it - Temporary holding space for the transactions that are going through the processor - Level 1 Cache (closest to the CPU in the core) First check or first storage of data Level 2 Cache (may also be part of the same core) Holds data, instructions, and/or results Secondary level or secondary storage of data Level 3 Cache - Still on the chip these days, may be shared throughout the cores Virtualization Support Run other operating systems within a single hardware platform The multiple operating systems share physical hardware components Virtualization in software was limited - Performance and hardware management challenges - Each part of the memory that is associated with each virtualized operating systems has to be kept separate, and also separate storage and transactions that are occurring, and all of these are independent to each individual virtualised system Virtualization added to the processor - Hardware is faster and easier to manage, more efficient at handling the separations - Intel Virtualization Technology (VT) - AMD Virtualization (AMD-V) Hyper-Threading Technology (HTT) One CPU acts like two - While the transfer process for information is happening in or out of the CPU, another transaction could be executing information at the same time Doesn’t actually work as fast as two 15% to 30% performance improvement Operating system must be written (support) for HTT - Windows XP and later (any modern OS) Processor Speed Real speed: CPU Clock - Historical qualification of speed - Megahertz (MHz) or Gigahertz (GHz) Total number of transactions that can occur in a single second (MHz = Millions, GHz = Billions) Actual speed - Combination of different factors - Clock speed, CPU architecture, bus speed, bus width, L1 cache size, L2 cache size, operating system capabilities CPU manufacturers have moved away from marketing performance in clock cycles No broadly accepted measure of performance - Use a benchmark that works for you Overclocking When fast isn’t fast enough Increase the clock speed past the rated value A balancing act - More power required - More heat created - At some point, the system becomes unstable Change the base clock (BCLK) - Need an unlocked CPU - Run a stress test to confirm the stability This will void your warranty - As you can break more than your CPU Integrated GPU (Graphics Processing Unit) Part of a video adapter, motherboard or CPU Graphics rendering requires a lot of work - Dedicated hardware speeds the process Intel and AMD Two solid CPU manufacturers - The differences are subtle - AMD tends to be a bit less expensive Costs Laptops Intel has a large portfolio of options Choosing a side - Historically, AMD is value and Intel is performance - This is a dynamic technology segment, which means it changes all the time Case Fans Cool air is pulled through a personal computer - Motherboard layout becomes important Lesser cables to block airflow Component location is key Always check for good airflow Devices, wiring, power Many different sizes and styles - And volume levels On-board Fans Designed to cool an entire adapter card Can be bulky May take additional adapter card space Usually seen on high-end graphic cards Fan Specifications Standard sizes Different speeds (if motherboard supports it) 80mm, 120mm, 200mm Variable speeds Different noise levels - Not all fans sound the same Heat Sink Air will pass through a heat sink Dissipate heat from the CPU through thermal conduction Copper or aluminium alloy (conduct heat efficiently) Fins/grid increase surface area - Heat is then transferred to the cooler air Thermal paste creates a good contact between the chip and the heat sink They get HOT Fanless / Passive Cooling No fans, no noise Specialized functions Video servers, TV set top box, satellite receiver, media server Functions are very controlled Silent operation Carefully measured thermal tests Low-power components - Heat sinks Liquid Cooling Coolant is circulated through a computer - Not a new concept o Mainframe computers High-end systems Gaming, Graphics Overclocking Expansion Cards Extend the functionality of your computer Relatively simple process Designed for end-user installation Install hardware You may need more than the motherboard provides Add a card Install a driver - Onboard Video Software for the operating system Video Cards Sound Cards Network Cards (Ethernet) Multi-port Ethernet For servers USB Expansion Card Storage Card SSD storage card eSATA Card External connection for SATA drives Documentation Check the motherboard documentation Number and type of slots Check the adapter card documentation - Minimum requirements – Hardware, Software - Knowledge base for the manufacturers - Support forums – what are other people saying? You may need to perform a driver installation before installing the hardware Driver Installation Check the manufacturer’s website for the latest version Uninstall previous drivers Some manufacturer might provide setup program Manual installation through Windows Device Manager Check the Device Manager for the status after installation to see if its working 3.6 Peripherals Printers Colour and B&W output - Paper documents - Photos AIO – All-In-One Printer, Scanner, Copier, Fax Connectivity - USB, Ethernet, 802.11 wireless, Bluetooth/Infrared Scanner Connected via USB or 802.11 wireless Different form factor - All-In-One (AIO) - Flatbed May include an ADF – Automatic Document Feeder Barcode / QR Code Reader Serial or USB Connector or 802.11 wireless Or with your phone - Built-in camera Display Devices Monitors The most popular output device Many different connections - VGA, DVI, HDMI, DisplayPort Many different standards - Different sizes and resolutions VR Headset Virtual Reality Motion Tracking Headset determines what you see X, Y, and Z axis Interact with a virtual environment - Gaming, Education, Art, Travel Optical / DVD Drives Store and read data with light - Small bumps read with a laser beam - Microscopic binary storage Read / Write media - Store backups and documents Read-only media - Data can’t be deleted - Common for video distribution Limited storage size - Dual-layer Blu-ray holds 50 GB Mouse USB Connection Or an adapter for old PS/2 interface Optical mice have few moving parts - May need the right surface - Glass may cause a problem Keyboard Connected via USB Or an adapter for old PS/2 interface Additional features may require additional drivers and/or software Touch Pads Integrated into the keyboard for laptops - May be a standalone device - Connected via USB or Bluetooth Replaces a mouse - Uses no additional space Signature Pads Small digitizer - And stylus USB connection Drivers may be required Gaming Input Game pad and Joystick - USB connected - Used exclusively for games Webcam Video Capture - Built-in camera - USB connected - 802.11 wireless Usually includes both audio and video - Specialized drivers and software Microphone Integrated into most new laptops and multimedia devices Connectivity - Analog – TRS (Tip / Ring / Sleeve) - Digital – USB Speakers Analog output devices - Compatible with our ears Connectivity - TRS (Tip / Ring / Sleeve) jacks at the back of your computer - Speaker output, audio adapter Headset Headphone and microphone Desk and mobile use - USB - TRS plug - Bluetooth Talk and listen - Desktop telephone - Mobile communication - Gaming Digital Projectors Not always LCD Common to see LCD Metal-halide Lamps - Very bright (very hot) light - Brightness measured in lumens - Relatively expensive Always let bulbs cool - Fans will run after shutting off - Keep it plugged in External Storage Device Storage outside the computer, often removable - Very portable, easy to move large files - USB flash drive, SSD, Hard Drives Many different connectivity options - USB, Thunderbolt, eSATA, etc Very large storage options - Very mobile - Can be a security concern KVM – Keyboard, Video and Mouse Use many computers with a single keyboard, video display, and mouse - Useful for data centres that have many servers Magnetic Reader / Chip Reader Point of sale terminal Method of payment for credit card Support for different format - Integrated Circuit in the credit card o Physically inserted into the reader - Magnetic Strip o Backwards compatibility Reader is USB connected to a point of sale (POS) terminal NFC – Near Field Communication / Tap-to-pay Device ~ 10 cm wireless range Built into many phones Integrates with a payment terminal Many different uses - Contactless payment systems - Identity token / Door key - Gaming and Entertainment Smart Card Reader Smart Card - Card with embedded circuitry - Used in credit cards, payment cards, identification cards Useful form of authentication Username, password, physical smart card Readers are built-in to the laptops or external - USB connected 3.7 Power Computer Power Supply Computer uses DC voltage Most power source provide AC voltages Convert 115 V AC or 220 V AC - To 3.3 V DC, 5.5 V DC, and 12 V DC Amp and Volt Ampere (amp, A) – The rate of electron flow past a point in one second “the diameter of a hose” Voltage (volt, V) – Electrical “pressure” pushing the electrons - “How open the faucet is” Power Watt (W) – Measurement of real power use Volts * Amps = Watts - 120 V * 0.5A = 60 W Current Alternating Current (AC) - Direction of current constantly reverses - Distributes electricity efficiently over long distances - Frequency of this cycle is important o US/Canada – 110 to 120 V of AC (VAC), 60 Hertz (Hz) o Europe – 220 to 240 VAC, 50 Hz Direct current (DC) - Current moves in one direction with a constant voltage Dual-voltage Input Options Voltage varies by country - US/Canada – 110 to 120 V of AC (VAC), 60 Hertz (Hz) - Europe – 220 to 240 VAC, 50 Hz Manually switch between 110 V / 115 V and 220 V / 230 V - Get your meter - Or use an auto-switching power supply Don’t plug a 115 V power supply into a 230 V power source 24-pin Motherboard Power Main motherboard power Old original ATX standard was a 20 pin connector Provides +3.3 V, +/- 5 V, +/- 12 V 24 pin was added for PCI Express power You can connect a 24-pin connector to a 20-pin motherboard - Some cables are 20-pin + 4-pin Power Supply Output Different voltages For different components Positive and negative voltage - Voltage is a difference in potential - The electrical ground is a common reference point - Depends on where you measure from At the front door of your house - The second floor is +10 feet - The basement is -10 feet +12 V - PCIe adapters, hard drive motors, cooling fans, most modern components - Some motherboard components - Many components are now using +3.3 V - M.2 slots, RAM slots, motherboard logic circuits +5 V +3.3 V Uncommon to find -12 V and -5 V on modern motherboards -12 V - Integrated LAN - Older serial ports - Some PCI cards -5 V (modern power supply most probably don’t supply) - Available for older ISA adapter cards - Most old ISA cards didn’t use it - Today’s motherboard doesn’t have ISA slots Sizing a Power Supply Power supplies are rated by Watts (W) Bigger isn’t necessarily better More expensive, and doesn’t speed up your computer Physical size is relatively standard Overall and by individual voltages Older cases and systems may have proprietary sizes Calculate the Watts required for all components - CPU, Storage Devices, Video Adapter - Many online calculators Video adapter cards are usually the largest power draw Many video card specifications list a recommended power supply wattage 50% capacity is a good rule of thumb - Power supply runs efficiently and there’s room to improve components in the future 3.8 Custom PCs Graphics Workstation Computer Aided Design (CAD) / Computer Aided Manufacturing (CAM) SSD High-end video High Speed storage Complex graphics Maximum RAM - Significant memory use Audio / Video Editing Workstation Specialized audio and video card - High quality audio - Powerful video Large fast hard drive - Constant disk writes - SSD Dual monitors - Edit in one monitor, view output in the other Virtualization Workstation Maximum RAM Every OS needs its own memory Maximum CPU cores - Constant processing - Needs an efficient CPU - Most virtualization apps can use multiple cores Gaming PC SSD High-end video / specialized GPU Graphically complex High-definition sound card Fast start and load times Multiple layers, atmosphere High-end cooling - High utilization for hours at a time NAS – Network Attached Storage Device Access from anywhere Media streaming Central location File sharing - Easy access Gigabit NIC (Network Interface Card) High speed transfers RAID array - Redundant Hard Drives Standard Thick Client A standard desktop computer Desktop applications Executable programs running in local memory and local CPU Meets recommended requirements for running the operating system - CPU, total RAM, disk space Thin Client Basic application usage - Applications usually run on a remote server - Virtual Desktop Infrastructure (VDI) - Local device is a keyboard, mouse, and screen Minimal operating system on the client - No huge memory or CPU needed to provide the remote desktop functionality Network connectivity - Big network requirement - Everything happens across the wire Custom PC Configurations Summary 3.9 Common Devices Thin Client Very little client configuration Mouse, Keyboard, network, monitor All the work is done on the server And power on Minimal OS on the client - Most of the OS is on the server - Apps are centralized on the server Few moving parts, if any - Inexpensive to buy - Easy to replace Thick Client Traditional computer With all of the requirements Local resources - Operating system - Device Drivers - Applications Ongoing support - Security patches - Operating system updates - Application updates Account Setup and Settings Centralized account management - Microsoft Active Directory - User account added to the directory Thin client - No local permission required Thick client - Device is added to the Microsoft domain - User authenticates to gain access to the thick client, and any other resources on that local device/network Laptop Thick client that moves from place to place Touchpad configuration Cloud-based or local drive Wireless connections Finger combinations and swiping Synchronization and backup Mobility brings additional administrative concerns Mobility in the office and elsewhere Additional security - VPN connectivity, local drive encryption Phone / Tablet Centralized management Touchscreen configuration Set by policy and requirements Synchronization and backup Lock codes and biometric access Application installations Mobile Device Manager (MDM) Cloud-based Wireless enabled - Includes VPN connectivity 3.10 SOHO Multifunction Devices Multifunction devices - Printer - Scanner - Fax - Network connection - Phone line connection - Print from web There are a lot of things that can go wrong - You are going to fix them Printer Drivers Specific to a printer model Get the right operating system drivers Get the right version of the operating system Windows 7, Windows 8/8.1, Windows 10 32-bit drivers are very different than 64-bit drivers You can’t mix and match drivers Printer Configuration Settings Duplex - Printing on both sides of the page without manually flipping over the paper - Not all printers can do this - Print multiple copies in their proper order - Non-collated Collate o Print 4 copies of page 1 first, then 4 copies of page 2 and so on - Collated o Prints page 1-4 first then repeat for 3 more times for 4 sets Orientation Portrait vs Landscape Quality - Resolution - Colour, Greyscale - Colour saving Wired Device Sharing USB type B - The most common connector - USB Type B on the printer - USB Type A on the computer Parallel - Only for legacy systems - Centronics interface on the printer - DB-25 on the computer Ethernet RJ-45 connector Wireless Device Sharing Bluetooth Limited Range 802.11 a/b/g/n/ac Infrastructure mode - Many devices using an access point 802.11 Ad hoc mode - No access points - Direct link between wireless devices Device Sharing Integrated print server - Prints directly to the printer - Jobs are queued on the printer - Jobs are managed on the printer o Web-based front-end o Client utility / application Cloud printing - Print to the cloud - Useful from mobile devices - The cloud sends to your printer - Google, Brother, HP, etc Sharing from an Operating System Network ports - Common on Windows devices - Commonly uses tcp/139, tcp/445, udp/137, and udp/138 Bonjour - Discover Apple devices on the LAN - Part of macOS - Can be added to Windows (iTunes, etc) AirPrint - Print from iOS devices to compatible printers Printer Data Privacy User authentication - Everyone can print - Set rights and permissions - Printing vs. managing the printer Print and scan caching - Click print - Local system creates a file of the output - Output file is sent to the print server spooler - Printing is done from the spool file - Spool file is deleted when done o But not always 3.11 Print Technologies Laser Printers Combine a laser, high voltage, charged ions, powdered ink, heat, and paper Very high quality Fast printing speeds Very complex - Many moving parts, requires on-printer memory, very messy on the inside Imaging Drum Image is drawn onto a photosensitive drum “Painted” with laser The drum is then put through the toner, and the toner sticks to the area where the laser hit - Transfers toner to the paper - Where it is heated, and permanently affixed to the output Can be separate from the toner cartridge - Or combined Fuser Assembly The process of permanently attaching that toner to the printed page is done using Heat and Pressure - Melt plastic toner powder - Permanently bond toner to paper Transfer Belt and Roller Colour laser printers - Cyan, Yellow, Magenta, Black Four separate toner cartridges Image is transferred from all cartridges to the single belt - And then to a single transfer roller Pickup Rollers Pick up paper - Should be a single page at a time - Problems if no paper is picked up or multiple sheets are picked up Should be periodically cleaned or replaced Separation Pad Pull just the top sheet from the paper tray Multiple sheets Small and inexpensive - Easy to clean or replace Duplexing Assembly Printers usually print on a single side Not both sides simultaneously Printing on both sides is a two-step process - Print side 1, print side 2 Automatic mechanism to “flip” the page Can be built-in to the printer - Or available as an add-on Cross-section of a Laser Printer The Laser Printing Process Replacing the Toner Cartridge Look for the messages Low doesn’t mean empty The toner can also contain the OPC (Organic Photoconductor) Drum - Sensitive to light, keep it in the bag Power down the printer first Remove packing strips from the new drum Laser Printer Maintenance Kit Standard maintenance kit - Replacement feed rollers, new fuser unit, etc Check the printer page counter to know when to perform maintenance Power down and replace the components Fuser unit are HOT Reset the page counter when you’re done Laser Printer Calibration Different toner cartridges print with different densities It can adjust the density of colours Can be automated or manual process - Check printer manual Laser Printer Cleaning The toner and paper dusts make laser printers dirty Check the manufacturer’s recommendations - Water, Isopropyl Alcohol (IPA) Inkjet (ink-dispersion) Printers Relatively inexpensive technology Quiet High-resolutions, and in colour Expensive ink - Proprietary Eventually fades Clogs easily Ink Cartridges Place drops of ink onto a page Pulled from a set of cartridges CMYK - Cyan, Magenta, Yellow, Key (Black) Print Head Some consumer printers integrate the print head into the ink cartridge Others separate the ink cartridges from the print head Feed Rollers Pick up and feed paper through the printer Must be clean and not worn Duplexing Carriage and Belt Ink Cartridges are moved over the paper Carriage may include its own print head Belt moves the carriage back and forth Inkjet Printer Calibration Align nozzles to the paper - Print test images - Lines should be crisp, and colours should align Printers includes a calibration option - May need to make minor adjustments Cleaning Print Heads Small droplets of ink And small holes in a print head Clogged heads are a big issue - Many printers automatically clean every day - Outputs has streaks or sections of missing colours Cleaning process can be started manually Some print heads/cartridges can be removed to manually clean Replacing Inkjet Cartridges Usually separate colours Take seconds to replace Some cartridges will combine these A few minutes to calibrate and prepare the cartridges Recycle the empty cartridges Clearing Jams Lots of turns and twists - Jam is inevitable Remove tray paper Remove paper from the path Check for any scraps of paper Thermal Printer White paper (Used to print receipts) - Turns black when heated - No ink Very quiet Paper is sensitive to light and heat Fade over time Feed Assembly Pull paper through the printer - Relatively small paper path Heating Element Full-length heating element - No moving print heads Thermal Paper Paper covered with a chemical - Changes colour when heated Cash registers, credit card terminal Looks like normal paper Thermal Paper Replacement Relatively inexpensive Different sizes Actual replacement process is easy Cleaning the Heating Element Liquid Cleaner - Isopropyl Alcohol (ISA) - Get a cleaning pen - Check the manufacturer recommendation Swab gently, usually small areas Use a cleaning card which cleans the head and paper pathways Removing Debris Relatively small amount of paper bits and dust Blow or wipe it out Avoid using a vacuum as it tends to build up and discharge static electricity Dot-matrix (Impact) Printers Print head with a small matrix of pins - Presses against a ribbon to make a mark on paper Good for carbon/multiple copies Low cost per page Noisy Poor graphics Niche use - Car Rental, Airports Dot-matrix Printer Head Moves back and forth Pins hit ribbon and paper One matrix - Must move across the page to print Printer Ribbon Fabric - One long ribbon - Never ending circle Easy to replace Once single unit Proprietary size - Specific to printer model Tractor Feed Paper pulled through with holes on the side of the paper Continuous paper feed Instead of using traction Perforations between pages Holes have to line up perfectly Printer Ribbon Replacement Replace when ink becomes too light Ink is eventually consumed Designed to be modular - Replace in less than a minute Print Head Replacement Takes a lot of abuse - Directly hit the ribbon and paper Gets hot Another modular part, look for a release lever or bar Replacing Paper Not as easy as laser printers Forms must be positioned correctly Paper must feed perfectly into holes Text needs to fit a predefined space Paper must feed without constraint - Make sure nothing in the way Virtual Printer No physical output No additional hardware required Output to a “digital” document No printer, no paper Useful for sending electronically - Easy to manage Print to File You need to print to a printer at work, but you’re at home Print to the work printer driver File will be in an output format specific to that printer But save it as a file Can’t open it with another program Must use command line to copy the file to the printer - i.e. copy filename LPT1: Print to PDF – Portable Document Format Adobe PDF - A one-way path from application to PDF - Cross-platform compatibility Proprietary Adobe format - Requires specialized software - PDF viewers built into many Internet browsers Many 3rd party tools available - Some applications will print to PDF without any additional software Print to XPS (XML Paper Specification) Microsoft XPS Similar use case to Adobe PDF - But XPS is included in Windows - And available all the way back to Windows XP Print to XPS, view in any operating system - If there’s an XPS reader Print to Image Print to a graphics image Not integrated into the OS For later image editing or sharing A feature of an application Some 3rd party image print drivers available - Applications may export graphics formats natively 3D Printers “Print” in three dimensions Additive manufacturing - Melt plastic filament in layers to create the objects - No machining process required Rapid Prototyping Create a 3D item based on an electronic model Design and create relatively quickly and inexpensive Deploy designs anywhere in the world - Or in space stations 4. Virtualization and Cloud Computing 4.1 Cloud Computing Infrastructure as a Service (IaaS) Sometimes called Hardware as a Service (HaaS) - Outsource your equipment You’re still responsible for the management and security Your data is out there, but more within your control Web Server providers Software as a Service (SaaS) On-demand software - No local installation, run through browsers - Why manage your own email distribution or payroll? Central management of data and applications - Maintenance and security are all maintained by the 3rd party provider A complete application offering Google Mail, Dropbox, Google Workspace, etc Platform as a Service (PaaS) No servers, no software, no maintenance team, no HVAC You don’t have direct control of the data, people, or infrastructure Trained security professionals are watching your stuff Put the building blocks together Someone else handles the platform, you handle the development Develop your app from what’s available on the platform SalesForce.com Cloud Deployment Models Private - Your own virtualized local data centre - Available to everyone over the internet Public Hybrid A mix of public and private Community - Several organizations share the same resources Shared Resources Internal Cloud - No resources are shared - Build your own cloud - Pay for everything up front (hardware, software and networking structure in data centre) No ongoing costs External Cloud - Share resources with a public cloud - Underlying infrastructure owned by a 3rd party - Cost may be metered or up-front Metered and Non-Metered Metered Cloud Services - You pay for what you use - Cost to upload, store, and download Non-Metered Services - You pay for a block of storage - No cost to upload and download - A flat fee Cloud Computing Characteristics Rapid elasticity - Scale up and down the application resources as needed - Seamless to everyone On-demand self-service - Adding software, networks, servers, storage is a challenge outside of the cloud - The cloud enables instant resource provisioning Resource Pooling - All of the computing power in one place - One large resource instead of many small resources - Use a very large piece of hardware instead of individual small hardware, and virtualize all those servers in that large hardware - So we can take advantage of the idle times of one server by using those resources with another running server - Pooled to serve multiple users through multi-tenant model (many users can access the same location’s resources) Measured Service - Cost and utilization are very closely tracked o Bandwidth set in and out of applications o Storage that is being used for applications o And the number of people using that application - Resource planning and granular chargebacks Off-site Email Applications Email is a staple Detailed Electronic Communication A challenge to maintain - Expensive hardware and storage - Trained support team - Ongoing backup and maintenance Cloud-based email hosting - Flat cost per user per month - Personal options may have no direct cost - Looks and feels the same for the user Microsoft 365, Google Mail Cloud File Storage Services Store your files in the cloud Access, share, and edit from anywhere Easy to collaborate - One place for all files Synchronization app - Store files on a local drive - The app synchronizes to the cloud - Sync the files to other devices Cloud storage providers - Dropbox, Google Drive, Microsoft OneDrive Virtual Application Streaming On-demand applications - No local installation - Globally distributed User starts the application - The components are downloaded as needed - If you don’t use a component, you don’t download it - User data is stored securely in the cloud Easy to update - The application is in one place - Some data is cached, only update the changes Application Streaming Mobile phones / tablets - Run an app (or a portion of an app) in real-time - Try many different apps or components - Can be cached locally for later use Like online advertising on mobile devices - Runs a part of an application in real-time, and allow you to use that app as if it was installed on your mobile device Applications for laptop / desktops - No complex deployment processes - Apps are only streamed if they are used - New applications are simply added to the cloud offering - Quickly manage and make changes Cloud-hosted Virtual Desktops A Virtual Desktop Infrastructure (VDI) in the cloud Access from almost any OS Users connect to a pre-built desktop Windows, Mac OS, Linux, iOS, Chromebook, web browser Virtual NIC - All communication in the desktop is local to the virtual desktop o If you are working on sensitive information on this virtual desktop, all of that information remains local to that virtual desktop o If someone was looking at the network communication between you and that virtual desktop, they would not be able to see the sensitive information - No sensitive information sent from the local device 4.2 Client-side Virtualization Virtualization One computer, many operating systems Separate OS, independent CPU, memory, network, etc Host-based virtualization Your normal desktop plus others Standalone server that hosts Virtual Machines (VM) But really one computer Enterprise-level Been around since 1967 - IBM mainframe virtualization The Hypervisor Virtual Machine Manager - Manages the virtual platform and guest operating systems - And keeps all of these resources separate May require a CPU that supports virtualization, which can improve performance Hardware management by the Hypervisor - CPU - Networking - Storage - Security Resource Requirements CPU processor support - Intel: Virtualization Technology (VT) - AMD: AMD-V Memory Disk Space Above and beyond host OS requirements Each guest OS has its own image Network - Configurable on each guest OS (Standalone, NAT, bridged, etc) - Virtual Switch Emulation vs. Virtualization Virtualization is a native operating system - Performing native OS processes - Identical to using a non-virtual system Emulation is one device running processes designed for a completely different platform/architecture - One device pretending to be another - Original code is used - Code is interpreted for running on the current hardware - This is commonly slower than running natively, and it is not easy to do Hypervisor Security Hypervisor is a sweet spot for the bad guys No significant vulnerabilities yet VM escaping - Malware recognizes its on a virtual machine - Malware compromises the hypervisor - Malware jumps from one guest OS to another Many hosted services are virtual environments - Malware on one customer’s server can gather information from another Guest Operating System Security Every guest is self-contained Use traditional security controls - Host-based firewall - Anti-virus, anti-spyware Watch out for rogue virtual machines Like a real computer The bad guys try to install their own system Self-contained VMs provided by 3rd parties can be dangerous - You have no idea what’s running on there Network Requirements Most client-side virtual machine managers have their own virtual (internal) network Shared network address - The virtual machine shares the same IP address as the physical host - Uses a private IP address internally - Uses NAT to convert to the physical host IP Bridged network address - The VM is a device on the physical network (local network) - Every VM can use DHCP to be able to obtain an IP address from the local DHCP server, or you can manually configure the IP addresses Private addresses - The VM does not communicate outside of the virtual network - Only able to communicate with VMs that is on that private network 5. Hardware and Network Troubleshooting 5.1 Troubleshooting Change Management Change control - A formal process for managing change - Avoid downtime, confusion, and mistakes - Corporate policy and procedures Nothing changes without the process - Plan for a change - Estimate the risk associated with the change - Have a recovery plan if the change doesn’t work - Test before making the change - Document all of this and get approval - Make the change The Troubleshooting Process Identify the Problem Information gathering - Get as many details as possible - Duplicate the issue, if possible Identify symptoms May be more than a single symptom Question users - Your best source of details Determine if anything has changed Approach multiple problems individually Who’s in the wiring closet? Break problems into smaller pieces Backup everything - You’re going to make some changes - You should always have a rollback plan What else has changed? - The user may not be aware - Environmental changes - Infrastructure changes There may be some clues - Check OS log files - Applications may have their own log files Establish a Theory Start with the obvious Consider everything Occam’s razor applies Even the not-so-obvious Make a list of all possible clauses - Start with the easy theories - And the least difficult to test Research the symptoms - Internal knowledge base - Google searches Test the Theory Confirm the theory Determine the next steps to resolve the problem Theory didn’t work? - Re-establish new theory or escalate, or call an expert The theory worked! - Make a plan Establish a Plan of Action Build the plan - Correct the issue with a minimum of impact - Some issues can’t be resolved during production hours / office hours Identify the potential effects - Every plan can go bad - Have a plan B and plan C Implement the Solution Fix the issue Implement during the change control window Escalate as necessary - You may need help from a 3rd party Verify Full System Functionality It’s not fixed until it’s really fixed - The test should be part of your plan - Ask your customers confirm the fix Implement preventative measures - Avoid this issue in the future Document Findings It’s not over until you build the knowledge base What action did you take? Don’t lose valuable knowledge What outcome did it have? Consider a formal database - Help desk case notes - Searchable database 5.2 Troubleshooting Computer Hardware Unexpected Shutdowns No warning, black screen May have some details in your Event Viewer Heat-related issue - High CPU or Graphics, Gaming - Check all fans and heat sinks - BIOS may show fan status and temperatures Failing hardware - Has anything changed? - Check Device Manager, run hardware diagnostics Could be anything - Eliminate what’s working Lockups System completely stops - May still see information on the screen, but it just freezes completely - Usually not much in the event log - Similar to unexpected shutdowns Check for any activity - Hard drive and status light - Try Ctrl-Alt-Del to bring up the task manager Update drivers and software patches Sometimes its low resources Has this been done recently? RAM, Storage space Hardware diagnostic may be helpful POST – Power On Self-Test Test major system components before booting the operating system - Main systems (CPU, CMOS, etc) - Video - Memory Failures are usually noted with beeps and/or codes BIOS versions can differ, check your documentation Don’t bother memorizing the beep codes - They are all different between manufacturers - Know what to do when you hear them POST and Boot Blank screen on boot - Listen for beeps - Bad video o May need to replace the external video adapter card - BIOS configuration issue o Especially when there are multiple options for video in your system BIOS time and setting - Maintained with the motherboard battery - Replace the battery Attempts to boot from an incorrect device - Set boot order in BIOS configuration - Confirm that the startup device has a valid operating system - Check for media in a startup device Continuous Reboot How far does the boot go before rebooting? BIOS only? OS splash screen? Bad driver or configuration - Press F8 during startup for Windows, and select “Boot from last known working configuration” Boot into safe mode (F8 for Windows 7) - This will load a basic configuration of windows - Disable automatic restarts in system properties Bad hardware - Try removing or replacing devices - Check connections and reseat No Power No power at the source No power from the power supply Get your multimeter to check the power socket or power supply Fans spin – no power to other devices - Where is your fan power connected? - No POST – bad motherboard? - Case fans have lower voltage requirement - Check the power supply output Overheating Heat generation CPUs, Video adapters, Memory Cooling systems - Fans and airflow - Heat sinks - Clean and clear of dusts Verify with monitoring software - Built into BIOS - Or 3rd party software Loud Noises Computer should not have a loud noise like grinding Rattling Loose components Scraping - Hard Drive issues Clicking - Hard drive or fan problems - Blown capacitor Pop Intermittent Device Failure Sometimes it works, sometimes it doesn’t Bad installation of adapter cards - Check and reseat - Use all the screws Bad hardware - Poor connection - Heat and vibration Indicator Lights POST codes on the motherboard Power lights Link lights on the NIC Speed light on the NIC Activity lights on the NIC Smoke and Burning Smell Electrical problem Always disconnect the power Locate bad components - Even after the system has cooled down - Replace all damaged components Crash Screen (BSOD) Windows Stop Error Contains important information Also written to event log Useful when tracking down problems - Sometimes more useful for manufacturer support Remember to take note of all these important information on the BSOD Every BSOD can have different information depending on what is causing the crash The Spinning Ball of Death (macOS) The macOS X Spinning Wait Cursor - Feedback that something inside the system is holding up the entire operating system from moving forward Sometimes the spin starts, but it never stops You never get back control of your computer Many possible reasons - Application bug - Bad hardware - Slow paging to disk Restart the computer - There may be details in the console logs Log Entries Windows - Event viewer - Boot logs o System configuration (C:\Windows\ntbtlog.txt) Linux - Individual application logs - /var/log macOS X - Utilities / Console.app Error Messages The details of an error message can make or break a troubleshooting session - Write down everything - Take a picture, make a video - Train your users The error might not make sense - Write it down anyway - The internet will tell you what it means - Spend your time troubleshooting the right things 5.3 Troubleshooting Hard Drives Disk Failure Symptoms Read / Write failure Slow performance “cannot read from the source disk” Constant LED activity on the hard disk Loud clicking noise Troubleshooting Disk Failures Get a backup Check for loose or damaged cables Check for overheating Check power supply Especially if problems occur after startup Especially if new devices were added Run hard drive diagnostic - From the drive or computer manufacturer - Preferably on a known good computer Boot Failure Symptoms Drive not recognized - Lights (or no lights) - Beeps - Error messages Operating system not found - The drive is there, but Windows OS is not Troubleshooting Boot Failures Check your cables Physical problems Check boot sequence in BIOS - Check for removable disk (especially USB) - Check for disabled storage interface For new installation, check hardware configuration - Try different data and power cables - Try different SATA interfaces Try the drive in a different computer RAID not Found Missing or faulty RAID controller RAID Stops Working Each RAID is different - Don’t start pulling drives until you check the console RAID Recovery For RAID 1, 5 and 10 - If you replace a new drive, the RAID array will recognize it’s a new drive, and it will begin rebuilding the data on that drive Crash Screens (BSOD) Windows stop error, or Apple spinning wait cursor May indicate a storage device issue - Diagnostics needed for drive and motherboard - Make sure to have backup SMART Errors Self-monitoring, Analysis, and Reporting Technology Use 3rd party or built-in utilities Avoid hardware failures Schedule disk checks Look for warning signs Built-in to most drive arrays Warning signs - Replace a drive in time 5.4 Troubleshooting Video and Display Issues No Video Image Is it connected? Input selection on monitor Check brightness control Swap the monitor HDMI, DVI, VGA, etc Image is dim Check both power and signal cable Try the monitor on another computer No windows after Windows loads - Use VGA mode (F8 during startup) o Basic mode configuration, that any monitor will be able to display Image Quality Problems Flickering, colour patterns incorrect Check cable pins Especially if missing a colour Distorted image and geometry - Check the OS refresh rate and resolution settings o Need to match the display specifications for monitor - Native resolution is important on LCD displays - Check or replace cable Disable hardware acceleration Troubleshoot with the software drivers Oversized images and icons - Resolution set too low o Lower = Larger Burn-in / Ghosting - A problem across all monitor type - That screen will lock that image in place, and still see part of it despite not displaying it anymore - Some displays will pixel-shift (move one pixel or two in different direction) when it recognises that an image has been displayed for an extended period of time o But you won’t notice it - LCDs have “image sticking” (a pixel that is stuck to a particular colour) o Remove by displaying a white screen over an extended period Other Video Issues Pixel problems - Stuck pixels (constantly bright) - Dead pixels (always black) Artifacts - Unusual graphics – check adapter (hardware acceleration) - Image persistence – Turn off and on the display - Motion trails o Disable advanced video features BSOD and Overheating - Video drivers - Monitor internal temperatures 5.5 Troubleshooting Mobile Devices and Laptops Laptop LCD Display Troubleshooting No display or dim video - Verify the backlight - Look closely, it may be barely visible - No backlight, and using older fluorescent style lights, need to replace inverters Confirm video with an external display to the laptop - Video good, but LCD bad - Replace the LCD display Flickering Video - Connector problem - Bad video cable - Bad video hardware that is connecting the LDC display to the motherboard of the laptop Input Issue Sticking keys - Difficult to clean - Laptop keycaps are very delicate Ghost cursor / Pointer Drift - Mousepad causes cursor to bounce around - Modify the configuration to check for palm press - Update drivers Num lock indicated lights - The letters are doubled as numbers Wireless Troubleshooting Multiple antennas - WiFi main and aux, Bluetooth - Antenna wires wrap around laptop screen Easy to accidentally disconnect during maintenance - No 802.11 wireless - No Bluetooth Check the connectors - Loose cables can cause intermittent wireless access Power Issues Battery not charging - Batteries lose capacity over time - Laptop charging hardware may be faulty No power - Check the external power adapter “brick” with multimeter - Master laptop reset o Hold power for 10 seconds o Each laptop is different External Monitor Issues Toggle Fn keys - Secondary functions - Toggle between LCD / external monitor / both Use external monitor - Bypass the LCD (but not the video hardware) by booting up with the external monitor Touchscreen Non-Responsive Touchscreen completely black or touchscreen not responding to input - Buttons and screen presses do not register Apple iOS restart Android device restart App Issues Apps not loading or slow performance Stop the app and restart Restart the phone Update the app to the latest version Unable to Decrypt Email Protect your email Built-in to corporate email systems Microsoft outlook Each user has a private key Encrypted communication channels You can’t decrypt with the key Install individual private keys on every mobile device - Use a Mobile Device Manager (MDM) Short Battery Life Bad reception - Always searching for signal - Enable airplane mode on the ground to conserve battery Disable unnecessary features 802.11 wireless, Bluetooth, GPS Check application battery usage Replace aging battery Overheating Phone will automatically shut down Charging / Discharging the battery, CPU Usage, Display light All these create heat Check app usage Avoid overheating damage Some apps use a lot of CPU Avoid direct sunlight Frozen System Nothing works - No screen or button response Soft or hard restart Ongoing problems may require a factory reset - Install latest operating system and reload No Sound from Speakers Check volume settings for both app and phone Bad software / delete and redownload Try headphones to see if its app or phone problem Sound starts but then stops Dueling apps / keep app in foreground Load latest software or factory reset GPS not Functioning Check settings to enable GPS Configure location mode Need a good view of the sky Swollen Battery Buildup of gas - Designed to self-contain - Do not open the battery packet / container o Significant fire risk Faulty battery - Stop using immediately - Dispose properly Device Disassembly Different than working on a desktop computer - Many different pieces - Intricately engineered - Tight quarters Taking it apart is easy Hard to get it back together Easy to break something - Very delicate parts Mapping the Puzzle Document and label Seems obvious when disassembling, but not obvious when assembling Cable locations - There are a lot of cables on laptops and mobile devices - Antennas, drives, video, etc Screw locations - There are a lot of screws - Different sizes - “Hidden” screws Organize Parts Laptops disassemble in sections Outer shell, keyboard, video connector, etc Step-by-step - Take pictures or videos - Use a big workspace Use containers to separate the sections - Glasses, boxes, etc - Magnetic grid - Multi-day projects should be sealed or protected Get the Right Information Refer to manufacturer resources Often provide step-by-step repair guides The internet provides the rest - Online written guides - YouTube videos Specialized sites can help - http://www.ifixit.com/ The Tools Use appropriate hand tools - Sometimes a single screwdriver - Get a good tweezer - Sometimes specialized tools Magnification will be needed For small devices Get a big anti-static cloth - Sometime soft to protect screens - Easy to break tiny parts 5.6 Troubleshooting Printers Testing the Printer Print or scan a test page - Built into Windows - Not the application Use diagnostic tools - Web-based utilities o Built into the printer - Vendor specific o Download from the manufacturer’s website - Generic o Available in LiveCD form Bad Output Streaks and blurs - Inkjet: Clean the print heads - Laser: Check for scratched photosensitive drum Faded prints, black pages Low toner or ink Ghost images - Laser printer optical drum not cleaned properly - Ghost or “shadow” from previous drum rotation Final Print Colour Pints in wrong colour Low ink in one cartridge Laser printer output smudges everywhere - Toner not fused to the paper - Fuser problem as it may not be hot enough Paper Jam Careful when removing as you can rip the paper or damage the internal components Paper not feeding - Check the tray - Pickup rollers Creased paper - Problems in the paper path - Check the paper weight Network Issues No connectivity - Power - Wired cabling / Wireless settings Access denied - Manage security settings of the printer Bad Output Garbled characters on paper Bad printer driver / wrong model Incorrect page description language (PCL or Postscript) Bad application Check with test page OS Issues Unable to install printer - Drivers are important OS updates - User must have proper rights - Check the printer driver o 32-bit vs. 64-bit Backed up print queue - Print server not working - Print spooler crash o Restart the spooler service o Change recovery options Error Messages Error codes on the printer display Low memory errors - Laser printers build the entire page in memory - Complex images and graphics consume more memory No Output Check the printer’s power - Check for display messages - Run a test print form the printer to check if it is able to work as a standalone device Check the connectivity - Print a test page from a computer - Check direct connection (via cable) - Try across the network - Test the operating system, network, drivers, and spooler Check other applications if Windows test print is working - Print from a different program Multiple Failed Jobs in Logs Corrupted print jobs - Print spooler will crash - Most spooler configuration will automatically restart Problems are logged Windows Event Viewer, Windows-PrintService One job may be causing the issue - Monitor the queue for details, and remove that one job 5.7 Troubleshooting Networks No Network Connectivity Do you have a link light on the NIC (Ethernet Cable)? Is it plugged in? Ping loopback (127.0.0.1) - Is the protocol stack working properly? - Availability and intermittent connectivity Ping local IP address Ping default gateway Checks local configuration, adapter, and link signal Connectivity on the local network Ping devices on router’s other side - Ping to Google DNS IP address 8.8.8.8 APIPA – Automatic Private IP Address If you turn on your computer and you don’t receive a response from a DHCP server, you might still be able to communicate with other devices within your local subnet A link-local address No forwarding by routers IETF has reserved 169.254.01 through 169.254.255.254 - First and last 256 addresses are reserved - Functional block of 169.254.1.0 through 169.254.254.255 Automatically assigned - Uses ARP (Address Resolution Protocol) to confirm the address isn’t currently in use Local Resources Unavailable Windows Shares - Server unavailable - Share permissions have been modified - Relies on DNS to find the server Printers - Device sharing printer (or printer) is unavailable - Printer permissions have been modified - Service is associated with a specific server - May be a cluster of servers - Problems may be related to the servers or the network path Email Limited or No Connectivity Windows alert in the system tray - “Limited or No connectivity” - “No Internet Access” Check local IP address An APIPA address will only have local connectivity If DHCP server is working properly and an address is obtained, perform ping tests - Local gateway, remote IP address Intermittent Connectivity Internet access Check system tray - Broken LAN icon is a loss of signal - Check for cable problem - Might have bad NIC Problem with switch or wireless access point - Bad interfaces - Router rebooting IP Conflicts Doesn’t occur if you have DHCP Windows will identify a duplicate And prevent a conflict Two identical IP address will conflict But static addresses can conflict Intermittent connectivity, if any Reboot or reset the NIC to restart the DHCP process Slow Transfer Speeds Router or infrastructure congestion - Overloaded network or devices Speed and duplex incompatibility Hardware issue with the adapter Or cabling Malware infection Low RF Wireless Signals Interference Signal strength Usually automatic, look for manual tuning Bounce and latency Transmitting signal, transmitting antenna, receiving antenna, etc Incorrect channel Something else is using our frequency Multipath interference, flat surfaces Incorrect access point placement - Locate close to the users Wireless Interference Predictable interference - Florescent Lights - Microwave ovens - Cordless telephones - High-power sources Unpredictable interference - Multi-tenant building Measurements - Signal strengths - Performance Monitor SSID not Found Network name doesn’t appear Too far away Other networks are there Local networks are louder Wireless router has disabled SSID broadcasting - It will never appear on a list - You can still manually connect
