Sybex CCNA 640-802 Chapter 4: Cisco’s IOS and SDM Instructor & Todd Lammle Chapter 4 Objectives • The Cisco router IOS • Enhanced editing • Administrative functions – – – – Hostnames Banners Passwords Interface descriptions • Verifying your configuration 2 Cisco Router IOS • Carries network protocols and functions • Connects high-speed traffic between devices • Adds security to control access • Provides scalability for growth • Supplies reliability Router Access • Console port (console) – Rollover cable, RJ-45 to DB-9, RJ45 to DB-25 • Auxiliary port (AUX) • Virtual terminal (VTY) Connecting To A Cisco Router Cisco 2811 Cisco 1841 Connecting To A Cisco Router Connecting Via Terminal Programs • Establish a connection – Physical connection through console • 9600 bits per second, data bits 8, stop bits 1, parity “none”, flow control “none” – Logical connection through VTY • Terminal programs • HyperTerminal, Microphone Pro, ProComm Plus, Telix, Tera Term Bringing up a Router • Boot-up process: 1: POST 2: Looks for the Cisco IOS from Flash memory 3: IOS loads & looks for a valid configuration; • startup-config • stored in nonvolatile RAM (NVRAM) 4: If a valid config is not found in NVRAM: • setup mode Bringing up a Router • Boot-up process: Setup Mode • Basic Management Setup • Extended Setup • Command-Line Interface Command-Line Interface (CLI) • More flexible than setup mode. • To use the CLI, just say No to entering the initial configuration dialog. • Initial prompt consists of two parts – Hostname – Greater than symbol (>) Logging into the Router • User mode: – Router> – Used mostly to view statistics • Privileged mode: – Router# – Used to view & change router configuration Overview of Router Modes • Global changes: – config terminal or config t – Changes made to running-config (DRAM) – To change the startup-config (NVRAM) • config memory or config mem Note: Any configuration changes need to be placed into RAM. Typing config mem or config net (from a TFTP host) will append the current running-config Configuration Modes • Global configuration mode – Router(config)# • Interface mode – Router(config–if)# • Line configuration mode – Router(config-line)# • Router configuration mode – Router(config-router)# Configuration Modes Configuration • • • • • CLI Prompts Interfaces Sub-interfaces Line Commands Routing Protocol Configurations Editing & Help Features Editing & Help Features • Commands starting with a certain letter Router#c? clear clock configure connect copy • Enhanced Editing Commands • Router-Command History • Gathering Basic Routing Information – show version Enhanced Editing Commands Enhanced Editing Commands (cont.) Router Command History Gathering Basic Routing Information Administrative Functions The administrative functions that you can configure on a router and switch are • • • • Hostnames Banners Password Interface descriptions Hostnames & Descriptions • Hostnames Router(config)#hostname todd todd(config)# • Descriptions Atlanta(config)#int e0 Atlanta(config-if)#description Sales Lan Banners • Purpose: welcome message • Types – exec: set EXEC process creation banner – incoming: set incoming terminal line banner – login: login banner – motd: set message of the Day banner • Delimiting character Banners Setting the Passwords • 5 passwords: – 1st two used to set your enable password • Used to secure privileged mode; Router>enable – Other three are used to configure a password in user mode via: • console port • auxiliary port • Telnet Passwords • Enable passwords Router(config)#enable password cisco Router(config)#enable secret cisco • • • • Auxiliary Password Console Password Telnet Password Encrypting Your Password Router(config)#service passwordencryption Passwords Passwords Passwords Passwords Passwords Interface Descriptions Setting descriptions on an interface is helpful to the administrator and, like the hostname, only locally significant. The description command is a helpful one because you can, for instance, use it to keep track of circuit numbers. Here’s an example: Atlanta(config)#int e0 Atlanta(config-if)#description Sales Lan Atlanta(config-if)#int s0 Atlanta(config-if)#desc Wan to Miami circuit:6fdda4321 You can view the description of an interface either with the show running-config command or the show interface command. Router Interfaces • Bringing up an Interface no shutdown shutdown show interface • Configuring an IP Address on an Interface Router(config)#int e0 Router(config-if)#ip address 172.16.10.2 255.255.255.0 Router(config-if)#no shut • Serial Interface Commands clock rate kilobits) & bandwidth (entered in Configuring The Time And Date Viewing, & Saving Configurations • Viewing & Saving Configurations – running-config saved in – startup-config saved in copy run start sh run sh start erase startup-config DRAM NVRAM Verifying Your Configuration Tools: – – – – – – show running-config show startup-config ping show cdp nei detail trace telnet Other Verification Methods • Verifying with the show interface command – Router#show interface ? • Verifying with the show ip interface command (layer 3 info) – Router#show ip interface – Router#show ip interface brief – Router#show controllers Router Components • • • • ROM Flash memory NVRAM RAM/DRAM Router Components • ROM – Read-only memory (ROM) – Bootstrap program – ROM monitor firmware – ROM monitor mode • (>) or (rommon 1>) Router Components • Flash memory – Erasable, programmable, readonly memory (EPROM) – Contains the Cisco IOS – Can store multiple IOS – “show version” command – “show flash” command Router Components • NVRAM – Nonvolatile random access memory (NVRAM) – Special type of RAM – Not cleared when router is rebooted – Startup configuration file – “show start” command Router Components • Random access memory (RAM) – Volatile – Information is not retain during router reboot – Running configuration – “show running-config” command – “show memory” command – “show buffers” command Summary • Go through all the written labs and review questions • Review answers in class 45