Network Technology
Foundations
© 2009 Certification Partners, LLC
All Rights Reserved
Copyright © 2004 ProsoftTraining, All Rights Reserved.
Lesson 1:
Introduction to Networking
Copyright © 2004 ProsoftTraining, All Rights Reserved.
Lesson 1 Objectives
•
•
•
•
•
•
•
•
•
Define telephony and convergence networking
Discuss the evolution of networking
Define the client/server model
Describe a Network Operations Center (NOC)
Describe peer-to-peer and server-based
networks
Identify network topologies
Identify network operating systems
Describe the OSI/RM and the packet-creation
process
Define major network protocols
Lesson 1 Objectives
•
•
•
•
•
•
•
•
•
(cont'd)
Describe the basics of LANs, WANs and IXPs
Identify common network components
Identify transmission media and types
Define wireless network technologies
Describe IEEE LAN standards
Describe T and E carriers
Define SONET/SDH
Describe how to download files with BitTorrent
Identify the requirements and benefits of
virtualization
Telephony and
Convergence Networking
• PSTN – still an integral part of the Internet
infrastructure because it furnishes most of the
long-distance connections
• Voice over IP (VoIP) – voice transmissions are
delivered in digital form as packets of data
using Internet Protocol (IP)
• Unified communications enable voice to be
converted into text, and vice versa
• Presencing – the ability for devices to
automatically track and report your location
and availability
Mainframes
• Mainframe (centralized) computing provided
the first practical network solution
– Retrieving information from mainframes
– Mainframe liabilities
– The future of mainframes
– Mainframes and cloud computing /
Software as a Service (SaaS)
Mainframe
Networking Model
Mainframe
Terminal
Terminal
Terminal
Terminal
Client/Server Model
• Client/server model (distributed computing) divides
processing tasks between the client and the server
Client
Server
Client/Server Model
(cont'd)
• Client/server model databases and SQL
• Client/server advantages
• Two-tier, three-tier and n-tier computing
Two-Tier
Computing Architecture
Data
Data
Data
Data
Mainframe
Minicomputer
Three-Tier
Computing Architecture
First Tier
Second (Middle)
Tier
Third Tier
Database
PC
Server
N-Tier
Computing Architecture
Second
(Middle) Tier
First Tier
Third Tier
Database
PC
Server
Server
Server
Network Operations
Center (NOC)
• A specific location from which a network is
managed, monitored and maintained
• Central point for network maintenance and
troubleshooting
• Generally includes multiple, redundant
network connections and redundant power
supplies
• Many have dedicated phone lines from a
separate provider and mobile phones to
ensure communication in an emergency
Networking Categories
• Peer-to-peer
– Microsoft peer-to-peer
– P2P
– Centralized or decentralized
• Server-based
– UNIX/Linux
– Microsoft LAN manger
– Microsoft Windows 2003 Server/2008 Server
Network Topologies
•
•
•
•
•
Bus
Star
Ring
Hybrid
Mesh
Network Operating Systems
• Operating systems that manage network
resources
• Interoperability
• Microsoft Windows
• UNIX/Linux
OSI Reference Model
• Defined by the International Organization for
Standardization (ISO) in 1983
• Gives developers universal concepts so they
can develop and perfect protocols that can
work with operating system and network
products developed by other vendors
• Explains the framework used to connect
heterogeneous systems
• Describes the process of packet creation (how
the layers communicate)
OSI Model Layers
Packets
• Packets consist of:
– Header (OSI/RM
layer information)
– Actual data
– Trailer (information
that validates the
packet)
• CRC
Packet Creation
(Adding Headers)
OSI/RM Protocol Examples
• Application layer
– SMTP, POP3, IMAP, HTTP, SMB, NFS
• Transport layer
– TCP
• Network layer
– IP
• Data link layer
– Ethernet, Token Ring
Major
Networking Protocols
•
•
•
•
Connection-oriented (stateful)
Connectionless (stateless)
Routable
Non-routable
TCP/IP
• Transmission Control Protocol / Internet
Protocol
• A collection of protocols
– TCP
– IP
– User Datagram Protocol (UDP)
• An open standard
IPX/SPX
•
Consists of:
– Internetwork Packet Exchange (IPX)
– Sequenced Packet Exchange (SPX)
Binding Protocols
• Binding protocols
– You must attach, or bind, protocols to your
NIC
• Protocols and binding order
Local Area
Networks (LANs)
• A group of computers connected within a
confined geographic area
• Commonly used for intra-office
communication
Wide Area
Networks (WANs)
• A group of computers connected over
an expansive geographic area
Internet Exchange Point (IXP)
• Internet backbones
• Backbone Network
Service
• Segments
New York
Backbone
Atlanta
Boston
Chicago
Phoenix
Backbone
Seattle
San
Francisco
Common
Network Components
• Network Interface
Cards (NICs)
• Hubs
• Bridges
• Routers
• Switches
• Channel Service Unit
/ Data Service Unit
(CSU/DSU)
• Modems
• Firewalls
Transmission
Media
•
•
•
•
Twisted-pair cable
Coaxial cable
Fiber-optic cable
Wireless media
Wireless Network Technologies
• Wireless communications use spread spectrum
technologies
– OFDM
– DSSS
– FHSS
• Wireless networking modes
– Ad-hoc
– Infrastructure
• Wireless access point (AP)
• Wireless AP security features
– Wired Equivalent Privacy (WEP)
– MAC address filtering
Wireless Network Technologies
(cont'd)
•
•
•
•
Wireless management software
Suitability of a wireless LAN
Attaching a wireless AP to a wired network
Next-generation (3G) wireless
Transmission Types
• Synchronous transmission
• Asynchronous transmission
• Data transmission flow
– Simplex
– Half duplex
– Full duplex
IEEE LAN Standards
•
•
•
•
•
•
•
IEEE 802.2
Ethernet/IEEE 802.3
IEEE 802.3u — Fast Ethernet
IEEE 802.3z and 802.3ab — Gigabit Ethernet
IEEE 802.3ae — 10-Gigabit Ethernet
IEEE 802.5 — Token Ring
IEEE 802.11 — Wireless Ethernet
T-Carrier System
T-Carrier
Data Transfer Rate
T1
1.544 Mbps
T2
6.312 Mbps
T3
44.736 Mbps
T4
274.176 Mbps
E-Carrier System
E-Carrier
Data Transfer Rate
E1
2.048 Mbps
E2
8.448 Mbps
E3
34.368 Mbps
E4
139.264 Mbps
E5
565.148 Mbps
SONET/SDH
• High-speed fiber-optic system
• Primarily used for network backbones, such
as the Internet backbone
• Transmissions carried out by optical carrier
(OC)
Downloading Files
with BitTorrent
• BitTorrent – a peer-to-peer (P2P) protocol that
you can use to download large files quickly
– Seeds
– Peers
– Torrent files
• When using BitTorrent, be careful not to illicitly
copy and distribute copyrighted material
Virtualization
• Virtualization allows you to run multiple virtual
operating systems and applications on a
single physical computer
– VMware
– Parallels
– VirtualBox
• Requirements for virtualization
• Benefits of virtualization
Lesson 1 Summary









Define telephony and convergence networking
Discuss the evolution of networking
Define the client/server model
Describe a Network Operations Center (NOC)
Describe peer-to-peer and server-based
networks
Identify network topologies
Identify network operating systems
Describe the OSI/RM and the packet-creation
process
Define major network protocols
Lesson 1 Summary









(cont'd)
Describe the basics of LANs, WANs and IXPs
Identify common network components
Identify transmission media and types
Define wireless network technologies
Describe IEEE LAN standards
Describe T and E carriers
Define SONET/SDH
Describe how to download files with BitTorrent
Identify the requirements and benefits of
virtualization
Lesson 2:
TCP/IP Suite and
Internet Addressing
Copyright © 2004 ProsoftTraining, All Rights Reserved.
Lesson 2 Objectives
• Define and describe the Internet architecture model and
various Internet protocols
• Describe the purpose of RFCs
• Explain the routing process
• Discuss routing protocols
• Describe port numbers and their functions
• Explain IP addressing, address classes, default subnet
masks, and the use of private IP addresses
• Define Internet Protocol version 6 (IPv6)
• Define the TCP/IP properties needed to configure a typical
workstation
• Describe various diagnostic tools for troubleshooting
TCP/IP networks
Internet Architecture
Application Layer
Transport Layer
Internet Layer
Network Access Layer
Requests for
Comments (RFCs)
• Maturity-level protocol states
– Experimental
– Proposed
– Draft
– Standard
• Additional protocol states
– Historic
– Informational
Internet Protocols
•
•
•
•
Network access layer
Internet layer
Transport layer
Application layer
Demultiplexing
Telnet
FTP
TFTP
TCP
SNMP
UDP
IGMP
ICMP
IP
RARP
ARP
ETHERNET
Introduction to Routing
•
•
•
•
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Direct routing
Indirect routing
Routing process
Routing information tables
Static vs. dynamic routing
Routing Protocols
• Interior vs. exterior protocols
• Routing Information Protocol (RIP) and RIPv2
• Open Shortest Path First (OSPF)
Port Numbers
• Classifying port numbers
– Well-known port numbers
– Registered port numbers
– Dynamic port numbers
Internet Addressing
field1.
field2.field3.field4
Each field represents one byte of data
Subnet Mask
• Distinguishes the network and host portions
of an IP address
• Specifies whether a destination address is
local or remote
• Network portion of an Internet address can be
determined using the TCP/IP ANDing function
Internet Address Classes
• Class A
– 0.0.0.0 to 127.255.255.255
• Class B
– 128.0.0.0 to 191.255.255.255
• Class C
– 192.0.0.0 to 223.255.255.255
• Class D
– 224.0.0.0 to 239.255.255.255
• Class E
– 240.0.0.0 to 247.255.255.255
Default Subnet Masks
for IP Address Classes
Private IP Addresses
Internet Protocol
Version 6 (IPv6)
• Shortcomings of IPv4
– Limited address space
– Lack of security
– Speed problems
– Configuration problems
• Strengths of IPv6
– More efficient and requires less
administrative overhead than IPv4
– Provides a practically unlimited number of
IP addresses
– Less dependent on routers
System Configuration
and IP Addresses
•
•
•
•
•
Default gateway
Loopback address
Broadcast address
Network and special-case source addresses
Normal TCP/IP workstation configuration
Diagnostic Tools
for Internet Troubleshooting
•
•
•
•
•
•
•
•
ping
tracert and traceroute
route
netstat
ipconfig — Windows
ifconfig — UNIX/Linux
arp
Network analyzers
Troubleshooting Considerations
•
•
•
•
DNS name resolution
Hosts file configuration
Static vs. dynamic IP addressing
Default gateway and subnet mask
Lesson 2 Summary
 Define and describe the Internet architecture model and
various Internet protocols
 Describe the purpose of RFCs
 Explain the routing process
 Discuss routing protocols
 Describe port numbers and their functions
 Explain IP addressing, address classes, default subnet
masks, and the use of private IP addresses
 Define Internet Protocol version 6 (IPv6)
 Define the TCP/IP properties needed to configure a
typical workstation
 Describe various diagnostic tools for troubleshooting
TCP/IP networks
Lesson 3:
Internetworking Servers
Copyright © 2004 ProsoftTraining, All Rights Reserved.
Lesson 3 Objectives
• Identify and describe the functions and features of
various internetworking servers
• Describe how each type of internetworking server
uses TCP/IP suite protocols
• Describe access-security features of an HTTP server
• Define MIME, and explain how MIME types are used
by HTTP and mail servers
• Define instant messaging (IM)
• Describe the functions of DNS
• Identify industry-standard Internet servers
• Discuss the uses and benefits of a Content
Management System (CMS)
Overview of
Internetworking Servers
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•
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File
Print
HTTP
Proxy
Mail
Mailing list
Media
•
•
•
•
•
•
•
DNS
FTP
News
Certificate
Directory
Fax
Transaction
File and Print Servers
• File servers — network servers that store data
files and programs that can be shared by
network users
• Print servers — network servers that allow
multiple users to send print jobs to the same
physical printer
• Line Printer/Line Printer Daemon (LPR/LPD) —
printing protocol in UNIX that allows users to
submit print jobs to network printers
HTTP Server Essentials
• The Web — a collection of computer systems
running the HTTP service
• Web server — has access to HTML documents that
are returned to a client in response to a request
HTTP Server Essentials
(cont'd)
• HTTP Servers and MIME
– Multipurpose Internet Mail Extensions
(MIME) — allow HTTP and e-mail
attachments to identify the files they must
use
– MIME types — identify the contents of a file
so browsers can display the contents
properly
HTTP Server Essentials
(cont'd)
• Additional HTTP server considerations:
– HTTP servers work with a variety of
operating systems
– Permissions — restrict or allow access to
system resources
• Operating system permissions usually
override HTTP server permissions
– Access control — specifies who has access
to system resources
HTTP Server Essentials
(cont'd)
• Additional HTTP server considerations:
– Aliases (or virtual directories)
• Flexible mapping of URL path names to
file names
– Logging — a log of requests handled by the
server
• Access data
• Referrer data
• Error data
HTTP Server Essentials
(cont'd)
• Additional HTTP server considerations:
– Monitor server and network bandwidth use
• Helps maintain consistent performance
• Helps to identify bottlenecks
• Helps to create a baseline against which
future network activity can be compared
HTTP Server Essentials
(cont'd)
• Common Web servers
– Apache server
– Microsoft Internet Information Services (IIS)
– Sun Java System Web Server
• Server-side technologies
– JavaServer Pages (JSP)
– Active Server Pages (ASP) and .NET
– PHP Hypertext Preprocessor (PHP)
• Open Database Connectivity (ODBC)
Database Servers
• Database — a file that stores information in a
series of tables and columns
• Relational database — a database consisting
of two or more tables related by a common
field
• Database server — a server that presents
relational databases and makes it possible for
remote individuals to access the data
• All database servers use SQL to create,
maintain and query databases
Proxy Servers
• Proxy server — an intermediary between a
network host and other hosts outside the
network
• Proxy servers:
– Provide enhanced security
– Manage TCP/IP addresses
– Speed Internet access by caching Web
documents
– Replace network IP address with another,
contingent address
Mail Servers
• Mail servers store/forward e-mail messages
using several protocols:
– SMTP — used to send messages
– POP3 — used to store and forward
messages (forces a user to download
messages before managing them)
– IMAP — used to store and forward
messages (allows a user to browse and
manage messages remotely)
• MIME is used to transmit files with e-mail
Instant Messaging (IM)
• Instant messaging runs on a mail server
• Use IM to:
– Type and view messages sent to one or
more recipients
– View the responses immediately
• IMs can be sent only to contacts who are
currently online
Mailing List Servers
• A mailing list server forwards an e-mail
message to every member on a distribution
list
• Mailing List Manager (MLM) — the interface
that allows you to configure a mailing list
server
• Public vs. private mailing lists
• Examples of public mailing lists:
– LISTSERV
– Majordomo
Mailing List Servers
(cont'd)
Media Servers
• A media server provides streaming audio and
video over a network
• Uses UDP ports and buffers to achieve the
effect of a real-time connection
– UDP is a connectionless protocol
– Buffer — cache of memory that stores
frequently used data to allow for faster
access times
DNS Servers
• DNS — mechanism used on the Internet to
translate host computer names into IP
addresses
– www.CIW-certified.com = http://74.206.104.14
• Hosts file — file referenced locally by
applications and commands for name-toaddress resolution
DNS Servers
(cont'd)
• DNS hierarchy
– Root-level domain — the top of the
hierarchy that contains entries for each toplevel domain
– Top-level domain — consists of categories
found at the end of domain names
– Second-level domain — includes the
businesses and institutions that register
their domain names with the top-level
domains
DNS Servers
(cont'd)
• DNS components
– Name server — server that supports nameto-address translation and runs the DNS
service
– Name resolver — software that uses the
services of one or more DNS servers to
resolve an unknown request
• DNS records — entries in DNS database that
provide additional routing and resolution
information
DNS Servers
• DSN server types
– Root
– Primary
– Secondary
– Caching-only
– Forwarding
(cont'd)
DNS Servers
.(root)
Domain name space
ie
se
(cont'd)
com
mx
net
ch
xyz
user1
iso
ftp
user2
www
DNS Servers
(cont'd)
• nslookup
– Used to query Internet domain name
servers to learn name-to-IP-address
mappings
– Example of nslookup one-time command:
• nslookup www.CIW-certified.com
– Used interactively by typing:
• nslookup
FTP Servers
• File Transfer Protocol (FTP) allows the transfer
of large files between file servers in real time
• Files of 2 MB or greater should be transferred
by means of FTP
• Sending files by means of FTP is faster than
with e-mail and HTTP
News Servers
• A news server uses Network News Transfer
Protocol (NNTP)
• Written text output
• Multi-person input
• Allows users to post information any time
• Can be used to create secure newsgroups by
enabling user-specific password protection or
through an SSL session
Certificate Servers
• A certificate server validates, or certifies,
encryption keys
• Keys — strings of text generated from
encryption algorithms that allow you to secure
communications for a company or group of
users
Directory Servers
• Identify all resources on a network, then make them
available to authenticated users
• Enable a company to reuse information in its directory
• Reduce/eliminate re-entry of user information for
applications that require it
• Help administrators manage applications and users
• Help users locate other users or e-mail addresses
• Locate and manage all company accounts
• Allow users inside and outside the network to use the
service
• Maintain a single database of e-mail contacts
Directory Servers
(cont'd)
• Directory server protocols
– X.500 — used to manage user and resource
directories
– X.500 offers:
• Scalability
• Synchronization
• Replication
– Lightweight Directory Access Protocol
(LDAP) — a TCP/IP suite protocol that
allows communication on both intranets
and the Internet
Fax and
Transaction Servers
• Fax servers
– Provide a centrally located fax system
– Consist of a bank of fax/modems
• Transaction servers
– Guarantee that all required databases are
updated when a transaction takes place
Choosing Web Server Products
• Apache Web server
– Used by almost half of all Web sites
– Supports UNIX and Windows
– Available free of charge
• Microsoft IIS
– Includes HTTP, FTP, NNTP, SMTP, certificate, ASP,
index (catalog) and transaction services
– Allows you to use a remote server to store and
retrieve files
Choosing Web Server Products
(cont'd)
• Sun Java System Web Servers
– Support many platforms, including Sun
Solaris, Windows, Linux, AIX and HP-UX
– Support JavaServer Pages (JSP)
technology and Java servlets
– Can use Java to connect to databases
– Can implement other server-side scripting
applications
Choosing Web Server Products
(cont'd)
• Java software and Web servers
– Java servlet — Java code that is compiled
and runs solely on Web servers
– Servlets allow:
• Chaining
• Connections to databases
• Near-universal support on systems
Content Management System
(CMS)
• CMS – allows you to easily create, store and
track all documents and information produced
by an organization
• Benefits
– Centralized management of content
– Ability to reuse content
– Increased collaboration
Content Management System
(CMS) (cont'd)
• Common CMS Services
– Role management
– Permission management
– Content publication
– Content editing
– Version control
– Indexing and searching
– Caching and replication
– Simplified backup
– Syndication
Content Management System
(CMS) (cont'd)
• CMS as a workflow management tool
– Helps managers and executives ensure that
users properly submit and manage content
• CMS requirements analysis
– Number of users
– Projected server load
– Storage capacity
Content Management System
(CMS) (cont'd)
• Managing a CMS
– Workflow management
– Content acquisition
– Standard tagging
– Taxonomic and social tagging
– Template creation and management
– Localization
– Personalization and portals
Content Management System
(CMS) (cont'd)
CMS and the content life cycle
Content Management System
(CMS) (cont'd)
• CMS security concerns
• Types of CMS
– Web CMS
– Enterprise CMS
• CMS vendors and products
Lesson 3 Summary
 Identify and describe the functions and features of
various internetworking servers
 Describe how each type of internetworking server
uses TCP/IP suite protocols
 Describe access-security features of an HTTP
server
 Define MIME, and explain how MIME types are
used by HTTP and mail servers
 Define instant messaging (IM)
 Describe the functions of DNS
 Identify industry-standard Internet servers
 Discuss the uses and benefits of a Content
Management System (CMS)
Lesson 4:
Hardware and
Operating System Maintenance
Copyright © 2004 ProsoftTraining, All Rights Reserved.
Lesson 4 Objectives
• Identify the characteristics of motherboards
• Identify common IRQ, I/O address and DMA
settings
• Identify SATA and SCSI traits
• Identify NICs and common peripheral ports
• Identify the characteristics of CDs, DVDs and
Blu-ray Discs
• Identify the characteristics of TV tuner cards,
HDMI connections and mobile computing
devices
Lesson 4 Objectives
(cont'd)
• Describe the importance of obtaining proper
software licensing
• Identify how to partition disks and prepare
logical drives
• Describe the characteristics of file system types
• Describe the uses of file system management
tools
• Identify and suggest corrective measures for
operating system boot problems and
application failures
• Identify methods to remotely manage and
troubleshoot workstations
Basic Hardware
and System Maintenance
• Fix hardware problems by ensuring:
– Components are plugged in
– Components are turned on
– Components are connected properly in
order to operate (such as connecting the
keyboard to the computer)
• Periodically clean hardware components
• Establish a preventive maintenance plan
Motherboard
• Main circuit board in a computer
• Must be securely fastened to system chassis
• Should never touch anything metal, except
through proper connections
• Most motherboard components are soldered
on and no longer replaceable
• If components fail (except for memory and the
microprocessor), the entire motherboard
needs to be replaced
IRQs, I/O Addresses and DMA
• Interrupt requests (IRQs) — hardware lines
used to identify when a device wants to
communicate with the processor
– Example: When a printer has finished
printing, it sends an interrupt signal to the
computer so the computer can decide what
to process next
• Input/output (I/O) address — memory location
that allows the system processor and system
devices to communicate
• Direct memory access (DMA) — allows a
device to access system memory directly,
bypassing the processor
Electronic Communication
• Binary numbering
– Converting decimal values into binary
– Bytes and bits
• Hexadecimal numbering
– Converting from hexadecimal into binary
and decimal
– Converting from binary into hexadecimal
• ASCII
Communication Basics
Serial communication
Communication Basics
(cont'd)
Parallel
communication
Mass Storage
Device Interfaces
• To communicate with a motherboard, mass
storage devices need to be connected to the
motherboard through an interface
• Two most common interfaces are:
– SATA
– SCSI
Serial ATA (SATA)
• SATA is currently the de facto standard for PCbased drives
• SATA devices are connected using a cable that
somewhat resembles a small Category 5
Ethernet cable
Small Computer
System Interface (SCSI)
• With SCSI, multiple devices can be connected
to a single controller in a daisy chain
configuration
• You can attach as many as 127 internal or
external SCSI devices to a single controller
• SCSI devices include hard disk drives,
printers, scanners and tape drives
• SCSI daisy chain must be terminated at both
ends and only at the ends
Network Interface Card (NIC)
• Each network device must have a NIC (or network
adapter card)
• The network adapter makes the physical
connection between the device and the network
cabling
• The network adapter converts the data from the
computer into a format appropriate for
transmission over the network
• Transceiver — the network adapter component
that handles data transmission
Common Peripheral Ports
Common Peripheral Ports
(cont'd)
• PS/2-style ports are for the mouse and
keyboard
• Serial ports
– Communicate using serial asynchronous
communication
– Are used for serial communication devices
• Parallel ports
– Communicate using parallel
communication
– Are used for parallel communication
devices
Common Peripheral Ports
(cont'd)
• USB ports
– Support asynchronous and isochronous
transmissions for data transfer
– Communicate using serial communication
– Support as many as 127 peripheral devices
in a daisy chain configuration
• FireWire (IEEE 1394)
– A high-speed serial interface to which you
can daisy chain as many as 63 peripheral
devices
– Good for devices that need to transfer large
amounts of data
Power Requirements
• Electricity is measured according to different
standards in North America and Europe
• Computing and networking equipment is also
manufactured to different standards
• When traveling from North America to Europe,
you will need:
– A special plug adapter
– A power inverter
Compact Disc—Read-Only
Memory (CD-ROM)
• CD-ROM — an optical storage device from
which data can be read only
• CD-ROM drives use common mass storage
interfaces
• Writable CD devices allow you to create, or
"burn," your own data and audio CDs
– CD-R (CD-recordable) — write data once
– CD-RW (CD-rewritable) — write data
multiple times
Digital Video Disc (DVD)
• DVD — optical storage device from which data can
be read only
• DVDs are similar to CD-ROMs but have higher
storage capacity
– Initial DVD standard provided 4.7 GB of storage
capacity
– Current DVD standards support dual-layer discs
with a storage capacity of 8.5 GB
– Double-sided disc standard supports 9.4 GB
when writing to one side or 17 GB total when
writing to both sides
Blu-Ray Discs (BDs)
• High-definition optical disc storage medium
that is designed to be the successor to DVDs
• Single-layer Blu-ray Discs can hold up to 25
GB of data
• Dual-layer Blu-ray Discs can hold up to 50 GB
of data
• BD-R — a write-once format
• BD-RE — a rewritable format
Optical Disc Drive
Maintenance
• Keep the drives closed when they are not in
use, and check all media for foreign matter
before inserting into the drive
• Optical discs should be handled only by the
edges
• Avoid scratching the disc surface
• Never directly touch or try to manually clean
the laser
• Brush away and vacuum accumulated dust
• Manually eject a stuck disc by inserting a wire
into the small hole on the face of the drive,
then pressing hard until the disc is ejected
TV Tuner Card
• Enables television signals to be viewed on a
computer monitor
• Four kinds of TV tuner cards:
– Analog TV tuners
– Digital TV tuners
– Hybrid tuner
– Combo tuner
High-Definition Multimedia
Interface (HDMI) Connections
• Transmit high-definition digital video and highresolution digital audio data
• Consist of 19 wires wrapped in a single cable
• Carry bandwidth of up to 5 Gbps
• Preserve the source digital signal by
eliminating the digital-to-analog-to-digital
conversion
• Should not run longer than 15 feet (5 meters)
to prevent signal degradation
Mobile Computing
• A person's ability to use technology while "on the go"
• Common devices and associated technologies:
– PDAs
– Bluetooth
– Smartphones
• iPhone
• BlackBerry
– Portable media players
• iPod and iPod Touch
• Zune
– Memory Sticks
– Secure Digital (SD) cards
– Google Android
Netbooks
• A more compact, Web-oriented version of the
standard laptop PC
• Relies on the cloud-computing model in which
the Internet is used for remote access to Web
applications
• Relies on wireless network connections
• Does not use a traditional hard disk; uses a
solid-state drive or a Secure Digital (SD) card
instead
• Easy to use and maintain
Software Licensing
• When you purchase software, you are purchasing
the right to use the software under certain
restrictions
• These restrictions are outlined in the license
agreement
• When you load software, the license agreement
typically displays during the installation process
• You must indicate that you have read and
understood the agreement before the installation
procedure will allow you to continue
Software Licensing
(cont'd)
• Apart from legal consequences, using
unlicensed software can also mean:
– No documentation
– No warranties
– No technical product support
– Greater exposure to software viruses,
corrupt discs or otherwise defective
software
– Ineligibility for software upgrades
Partitions and
Logical Drives
• When installing an operating system on a new
computer or after recovering from a hard disk
failure, prepare the hard disk for use by:
– Partitioning the hard disk
– Creating logical drives
– Formatting logical drives
Disk Partitioning
• Partition disks to
divide total
storage space
• Primary partition
— the system’s
boot drive, used
for system startup
• Extended partition
— the remaining
drive space after
you create the
primary partition
Logical Disk Drives
• A disk partition must
be assigned a logical
drive identifier
• A primary partition is
treated as a single
logical drive
• An extended partition
can be divided into
multiple logical drives
(Drives D and E in
figure)
Logical Drive Format
• Low-level format
– Prepares the hard disk before disk partitions
can be defined
– Primarily the responsibility of the hard disk
manufacturer
• High-level format
– Logical drive formatting that prepares the drive
for use by the operating system
– Creates the file system root directory and the
files used to track disk space use
File System Types
• Primary partitions and logical drives must be
formatted so the operating system can use
them
• Formatting creates the file system by adding
information about how files should be stored
on the drive to organize and manage disk
storage
• File system types include:
– FAT32 and NTFS (Windows)
– Ext3/4 and ReiserFS/4 (Linux)
File and
Directory Permissions
• NTFS allows you to set permission bits on
system resources
• In NTFS, you can protect files so that only
certain users or groups of users can read
them
• Concerns
– If permissions are applied improperly, users
may take security for granted
– Improperly set permissions can disrupt an
operating system
Convert Utility
• Information about the files on an NTFS volume
and their attributes is stored in the master file
table (MFT)
• Convert utility — used to convert a partition or
logical drive from FAT32 to NTFS
convert drive /FS:NTFS [/v]
Disk Defragmenter Utility
• As files are created and deleted, a partition
can become severely fragmented
• Fragmented files are no longer located in
contiguous clusters
• You can use the Disk Defragmenter utility to
defragment hard disks and put files back
together in a contiguous format
Chkdsk Utility
• You can use the Chkdsk utility in Windows to:
– Create and display a status report for a disk
based on its file system
– List and correct errors on the disk
– Display the status of the disk in the current
drive
Disk Cleanup Utility
Use the Disk Cleanup utility to recover the disk
space used by:
– Temporary files
– Unused applications
– Files in the Recycle Bin
– Files you downloaded as part of Web pages
– Files created when Chkdsk attempted to
recover lost file fragments
Backup and
Restore Utilities
• Keep a current backup of all data files to
ensure that data can be recovered if a hard
drive fails
• When you back up data, you store copies of
folders and files to a source other than your
computer's hard disk
• You restore data when you need to access the
backed up data
Troubleshooting Software
• Software troubleshooting refers to anything
other than problems caused by system
hardware
• Software problems can be caused by:
– Bugs
– Corrupted files
– Incompatibilities
– Virus infections
Operating System
Boot Problems
• Error: No operating system
– Bad or missing command interpreter
– Missing ntldr (Windows)
– Kernel not available (Linux)
– Operating system files missing
– Hard disk or controller failure
Blue Screen
of Death (BSOD)
• Blue screen that indicates that a critical
operating system failure has occurred during
startup
• To troubleshoot:
– Restart the system in Safe mode and use
the Last Known Good Configuration option
– Reinstall the operating system
– Attempt to diagnose the problem by
parsing the dump file
System Lockup
• Lockup causes:
– Applications that are incompatible with the
operating system or with a hardware
component
– IRQ conflicts
– Related problems that you may be able to
find in the system log file
• Power down your system by manually
pressing and holding down the power key for
five seconds
Application Failures
• Application failure causes:
– Low system RAM
– Current logon environment crashes
– Improper permissions
– Improper system resolution or color levels
• View the system log
– Windows Event Viewer
– Linux/UNIX "messages"
Application Failures
(cont'd)
• Windows protection error causes:
– Device drivers that may not be written
specifically for your operating system
– Applications or utilities that attempt to
bypass the operating system and directly
access local system hardware
• Application installation and loading failures:
– Application will not load into memory
– Application can cause an illegal operation,
resulting in the blue screen of death
– Application may not install at all
Remote Management
and Troubleshooting
• Telnet — TCP/IP command that establishes a
remote connection with a server
• SSH — protocol and command interface that
can gain secure access to a remote computer
• VNC — program that controls a remote
computer
– VNC consists of two components:
• A server that listens to a specific port
• The viewer, which shows the remote
system’s logon environment
Remote Management
and Troubleshooting (cont'd)
• Remote Desktop — Windows service used to
gain access to a Windows session that is
running on another computer
– Allows multiple users to have active
sessions on a single computer
– Allows you to switch from one user to
another on the same computer
• Remote Assistance — Windows service used
to seek help from a remote user
Lesson 4 Summary
 Identify the characteristics of motherboards
 Identify common IRQ, I/O address and DMA
settings
 Identify SATA and SCSI traits
 Identify NICs and common peripheral ports
 Identify the characteristics of CDs, DVDs and
Blu-ray Discs
 Identify the characteristics of TV tuner cards,
HDMI connections and mobile computing
devices
Lesson 4 Summary
(cont'd)
 Describe the importance of obtaining proper
software licensing
 Identify how to partition disks and prepare
logical drives
 Describe the characteristics of file system
types
 Describe the uses of file system management
tools
 Identify and suggest corrective measures for
operating system boot problems and
application failures
 Identify methods to remotely manage and
troubleshoot workstations
Lesson 5:
Network Security and
Personal Privacy Protection
Copyright © 2004 ProsoftTraining, All Rights Reserved.
Lesson 5 Objectives
• Define security
• Describe computer viruses and worms
• Identify various network attacks and ways to defeat
them
• Describe authentication principles
• Explain the three major types of encryption
• Describe firewalls, common firewall topologies and
security zones
• Describe the function of a VPN
• Describe security audit principles
• Describe the function of a UPS
• Discuss Internet-related personal privacy issues
• Discuss Internet-based challenges against which
users should be protected
Defining Security
• Security — a set of procedures designed to
protect transmitted and stored information, as
well as network resources
• Security administrators must determine which
people can take appropriate actions on
specific items at the appropriate time
Viruses and Worms
• Virus — code that causes damage to systems
• Virus types
– Macro/script
– File infecting
– Boot sector
– Stealth
– Polymorphic
– Retro
• Worm — similar to virus but automatically
replicates
Overview of
Network Attack Types
•
•
•
•
•
Spoofing
Man in the middle
DOS
Distributed DOS
Brute force
•
•
•
•
•
Dictionary
Back door
Buffer overflow
Trojan
Social
engineering
To avoid attacks:
• Install stable updates
• Use encryption
• Be suspicious of information
requests
• Remain informed
Defeating Attacks
• OSI/RM security services
– Authentication
– Access control
– Data confidentiality
– Data integrity
– Non-repudiation
• Updates
Authentication
• Three authentication methods
– What you know
– What you have
– Who you are
• Passwords
– Strong passwords
– Age passwords appropriately
• Account lockout — disables accounts after a given
number of invalid passwords have been entered
• Account reset — enables you to choose whether
accounts reset automatically after a given interval
Authentication
(cont'd)
• Managing passwords
– Use password manager software to help
store and manage your passwords
– Example: KeePass
• Password generators
– Algorithms that receive input from a
random or pseudo-random number
generator and then automatically generate
a password
Digital Certificates
•
•
•
•
•
Provide authoritative identification
Verify the sender's identity
Use the X.509 standard
Are used for non-repudiation
Contain digital signatures
– Certificate authority (CA)
Public Key Infrastructure (PKI)
• PKI CA servers:
– Are repositories for managing digital
certificates
– Enable the secure creation and
management of digital certificates
– Provide the ability to revoke an invalid key
• If you need a certificate for a server, use PKI
Encryption
• The primary means to ensure privacy across
the enterprise
• Symmetric-key encryption
– One key to encrypt and decrypt
– All parties must know and trust one another
• Symmetric algorithms
– DES
– Triple DES
– AES
Encryption
(cont'd)
• Asymmetric-key encryption
– Uses a key pair (one public, one private)
– Used to create a digital signature
• Asymmetric algorithms
– RSA
– DSA
Encryption
(cont'd)
• Hash encryption
– Uses a hash table that contains a hash
function
– Used for information that will not be
decrypted or read
• Hash algorithms
– MD2, MD4 and MD5
– SHA
Encryption
(cont'd)
• Pretty Good Privacy (PGP) — uses a
combination of the three encryption types
• GNU Privacy Guard (GPG) — the open-source
version of PGP
• PGP and GPG:
– Use symmetric-key encryption to scramble
the original message you want to send
– Use asymmetric-key encryption to encrypt
only the symmetric key you just used
– Use hash encryption to "sign" the message
and ensure that no one can tamper with it
Firewalls
• A firewall is a secure computer system placed
between a trusted network and an untrusted
one, such as the Internet
– The most common location for a firewall is
between a corporate LAN and the Internet
• Allows users from a protected network to
access a public network while simultaneously
making the protected company's products and
services available to the public
Internal and
Personal Firewalls
• Internal firewall — resides inside your
company's internal network
– Internal firewalls can:
• Protect sensitive systems
• Isolate networks that still need Internet
connectivity but which use software that
may cause problems with other company
resources
• Personal firewall — offers protection for an
individual system
Packet Filtering
• Packet filter — inspects each packet for
predefined content
• Packet filters filter data based on the following
fields in the packet:
– Source IP address
– Destination IP address
– TCP/UDP source port
– TCP/UDP destination port
Proxy Servers
• A proxy server replaces the network IP
address with a single IP address
• Provides the following services:
– Hiding of network resources
– Logging
– Caching
• Application-level gateway — a proxy between
the Internet and your internal system at the
application level
• Most firewalls are combinations of packet
filtering and application-level gateways
Network Address
Translation (NAT)
• The practice of hiding internal IP addresses
from the external network
• Two ways to provide NAT
– Configure masquerading on a packetfiltering firewall
– Use a proxy server to conduct requests on
behalf of internal hosts
Accessing
Internet Services
• If Internet access is required and a network is
located behind a proxy server or firewall, you
may have problems accessing Internet
services that use ports other than common
ports
• To avoid these problems:
– Make sure the network has access to all
Internet-related protocols used by the
company
– Make sure that the IP addresses assigned
to the computers in your network have
permission to access the Internet
Troubleshooting
Access Through Firewalls
• Firewalls can cause a bottleneck
• Firewalls may not allow home-based account
access to the corporate e-mail server
• To troubleshoot firewall problems:
– Verify that you are using the correct IP address
and subnet mask
– Check your default gateway and verify that the
computer can communicate with systems on
the same subnet
– Verify DNS resolution
– Try to use multiple protocols on the Internet
Firewall Topologies
• Common firewall implementations
– Packet filter
– Dual-homed bastion host
– Triple-homed bastion host
– Screened subnet (back-to-back firewalls)
• Bastion host — a computer that houses
various firewall components and services, and
is connected to a public network
Packet Filter Topology
Dual-Homed Bastion Host
Triple-Homed Bastion Host
Screened Subnet
Security Zones
• Demilitarized zone (DMZ) — a mini-network that
resides between a company's internal network and
the external network
• Intranet — a security zone available only to
authorized organization employees
• Extranet — a private network that allows selected
access to outsiders only after they provide
authentication information
• Virtual LAN (VLAN) — a logical grouping of hosts,
generally not implemented by a firewall
Virtual Private Network (VPN)
• A technique that allows secure
communication across long distances, usually
for a company extranet
• In a VPN, the Internet is often the corporate
network backbone
• Appropriate for any organization requiring
secure external access to internal resources
• All VPNs are tunneling protocols — encryption
occurs at the source and decryption occurs at
the destination
Virtual Private Network (VPN)
(cont'd)
• VPN protocols
– Point-to-Point Tunneling Protocol (PPTP) —
works only with IP protocols
– Layer 2 Tunneling Protocol (L2TP) — works
with non-IP protocols
– IP Security (IPsec) — more flexible than
PPTP or L2TP because you can specify
different authentication methods
Remote Access Server (RAS)
• Requires the use of dial-up modems to dial up,
connect and log on to RAS
• Offers security through a callback feature
– A user logs on to RAS
– The user is disconnected
– RAS calls the user back to ensure the call
was made from an authorized computer
Security Audit
• Review of the state of the network
• Auditing process:
– Conduct a status quo analysis
– Conduct a risk analysis
– Make recommendations based on findings
Uninterruptible
Power Supply (UPS)
• Device that allows a computer to keep running
temporarily when the primary power source is
lost
• Can be configured to:
– Shut down entire systems automatically
– Shut down only certain components
automatically
– Place components into minimal power use
mode until the system is shut down
manually
Personal Privacy
and the Internet
• Internet privacy – the ability to control what
information you reveal about yourself over the
Internet and to whom (or what) you reveal it
• Anonymizing tools – Internet components and
application features that make the user's
Internet activity untraceable
– Browser privacy mode features
– Proxy servers
– VPN servers
– Anonymizer Web sites
Internet Privacy
• Browser privacy mode – no cache or history
of your browsing sessions are kept
• Browsers with privacy mode features
– Mozilla Firefox
– Microsoft Internet Explorer (InPrivate)
– Google Chrome (Incognito)
– Apple Safari (Private Browsing)
• Use Web sites that provide anonymizer
services to thwart tracebacks, hide your
online identity and bypass proxy servers
Ethics of
Anonymous Browsing
• Anonymous browsing hides your identity
– You can use anonymous browsing to
minimize risk if you engage in online
behavior that may be potentially dangerous
• People can also engage in anonymous
browsing for unethical or illegal purposes
– Anonymous browsing allows a person to
browse the Web without leaving behind any
incriminating evidence
Internet Fraud
• Scams or other deceptive practices committed
via the Internet, usually for the purpose of
monetary gain or identity theft
– Auction and retail scams
– Business opportunity scams
– Investment scams
– Credit card scams
– Purchase scams
– Money transfer scams
– Dating scams
Identity Theft
• Fraud committed in your name by someone
else who has illicitly gained access to your
personal information
• Methods used by identity thieves
– Dumpster diving
– Skimming
– Phishing
– Address changing
– Stealing
Phishing, Pharming
and Anti-Phishing Software
• Phishing – a form of social engineering that
attempts to gather personal and financial
information from unsuspecting victims by
sending e-mail and luring the user to a
legitimate-looking site, then requesting
passwords, accounts numbers, etc.
• Pharming – the act of installing malicious
code on personal computers or servers that
redirects Internet traffic from a legitimate Web
site to an identical-looking bogus Web site
• Anti-phishing software – program designed to
identify phishing content contained in Web
sites and e-mail messages
Personal Protection
and the Internet
• Online stalking
– Occurs when a person ("stalker") stealthily
pursues, harasses and/or preys upon another
person using online venues such as e-mail,
chat rooms and social networking sites
• Cyberbullying
– The willful harm inflicted on others through the
use of information and communication
technologies
• Internet addiction
– Many users spend so much time involved with
online games, social networking, blogging,
instant messaging and so forth that they are
missing out on real-world experiences
Lesson 5 Summary
 Define security
 Describe computer viruses and worms
 Identify various network attacks and ways to defeat
them
 Describe authentication principles
 Explain the three major types of encryption
 Describe firewalls, common firewall topologies and
security zones
 Describe the function of a VPN
 Describe security audit principles
 Describe the function of a UPS
 Discuss Internet-related personal privacy issues
 Discuss Internet-based challenges against which
users should be protected
Network Technology Foundations





Introduction to Networking
TCP/IP Suite and Internet Addressing
Internetworking Servers
Hardware and Operating System Maintenance
Network Security and Personal Privacy
Protection