sybex ccna 640-802 chapter 4: cisco’s ios and sdm instructor & todd lammle
TRANSCRIPT
Chapter 4 Objectives
• The Cisco router IOS• Enhanced editing• Administrative functions
– Hostnames– Banners– Passwords– Interface descriptions
• Verifying your configuration
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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, RJ-
45 to DB-25
• Auxiliary port (AUX)
• Virtual terminal (VTY)
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-configstartup-config• stored in nonvolatile RAM (NVRAM)
4: If a valid config is not found in NVRAM:• setup modesetup mode
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 running-config
(DRAM)– To change the startup-configstartup-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-configrunning-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
• CLI Prompts
• Interfaces
• Sub-interfaces
• Line Commands
• Routing Protocol Configurations
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 versionshow version
Administrative Functions
The administrative functions that you can configure on a router and switch are
• Hostnames• Banners• Password• Interface descriptions
Hostnames & Descriptions
• HostnamesRouter(config)#hostname todd
todd(config)#
• DescriptionsAtlanta(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
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 useruser mode via:
• console port• auxiliary port• Telnet
Passwords
• Enable passwordsRouter(config)#enable password cisco
Router(config)#enable secret cisco
• Auxiliary Password
• Console Password
• Telnet Password
• Encrypting Your PasswordRouter(config)#service password-
encryption
Interface DescriptionsSetting 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 Interfaceno shutdownshutdownshow interface
• Configuring an IP Address on an Interface
Router(config)#int e0Router(config-if)#ip address 172.16.10.2
255.255.255.0Router(config-if)#no shut
• Serial Interface Commandsclock rate & bandwidth (entered in
kilobits)
Viewing, & Saving Configurations
• Viewing & Saving Configurations– running-configrunning-config saved in DRAM– startup-configstartup-config saved in
NVRAMcopy run start
sh run
sh start
erase startup-config
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– Read-only memory (ROM)– Bootstrap program– ROM monitor firmware– ROM monitor mode
• (>) or (rommon 1>)
Router Components
• Flash memory– Erasable, programmable, read-
only 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