router components semester 2 chapter 4. table of contents more on components the show command...
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TRANSCRIPT
Table of Contents
More on Components
The Show Command
Network Neighbor Routers
Basic Network Testing
External Configuration A router can be configured from four
separate sources: Console port (used to initially configure the
router) WAN/LAN links (attach through hub or switch
using a patch cable) Auxiliary port (needs a modem) TFTP server installed on the network
The easiest place to configure from is the console port. Attach a rollover cable from the router to your
computer COM1 or COM2 port Open HyperTerminal to log in
Internal Configuration
Review “Router Basics” section in Ch.2/3 Powerpoint.
RAM NVRAM Flash ROM
InterfacesConsoleAuxiliary
RAM NVRAM Flash ROM
InterfacesConsoleAuxiliary
As the router is booted, the following is loaded into RAM’s Working Storage.
RAM Specifics
RAMCommandExecutive
InternetworkOperating
System(IOS)
ProgramsActiveConfig
FileTables Buffers
Programs include the bootstrap program that • tests the equipment (POST) • and locates the IOS.
RAM Specifics
RAMPrograms
RAM Specifics
RAMInternetwork
OperatingSystem(IOS)
Programs
Once the IOS is located by the bootstrap program, it is loaded in to RAM.
RAM Specifics
RAMCommandExecutive
InternetworkOperating
System(IOS)
Programs
Part of the IOS is the Command EXEC. This is the program that translates the commands you type into a language that the IOS can understand.
RAM Specifics
RAMCommandExecutive
InternetworkOperating
System(IOS)
ProgramsActiveConfig
File
Once the IOS is initialized, it looks for an active configurations file (usually in NVRAM) and loads it. This file tells the router specifically what to do.
RAM Specifics
RAMCommandExecutive
InternetworkOperating
System(IOS)
ProgramsActiveConfig
FileTables
The tables are loaded from the configuration file including...• ARP Tables• Routing Tables
RAM Specifics
RAMCommandExecutive
InternetworkOperating
System(IOS)
ProgramsActiveConfig
FileTables Buffers
Finally, all leftover memory in RAM is used as the buffer for processing incoming and outgoing packets.
Router Status Commands
On the next slide, you will see a graphic displaying the most common show commands.
Be sure to copy this graphic in your notes.
You need to know which component of the router the show command accesses and what each show command displays.
FlashNVRAMRAM
Internetwork Operating System
ProgramsActive
ConfigurationFile
Tablesand
Buffers
BackupConfiguration
File
OperatingSystems
Inte
rface
sRouter#show version Router#show flash
Router#show interfaces
Router#show processes CPURouter#show protocols
Router#show running-configRouter#write term
Router#show memRouter#show stacksRouter#show buffers
Router#show startup-configRouter#show config
Show Commands Defined show version -- displays the configuration of the system
hardware, the software version, the names and sources of configuration files, and the boot image
show startup-config (show config on Cisco IOS 10.3 or earlier) -- displays the backup configuration file
show flash -- shows information about the Flash memory device
show interfaces -- displays statistics for all interfaces configured on the router
show processes -- displays information about the active processes
show protocols -- displays the configured protocols; shows the status of all configured Layer 3 protocols
Show Commands Defined show running-config (write term on Cisco IOS
10.3 or earlier) -- displays the active configuration file
show memory -- shows statistics about the router's memory, including memory free pool statistics
show stacks -- monitors the stack use of processes and interrupt routines and displays the reason for the last system reboot
show buffers -- provides statistics for the buffer pools on the router
CDP
In order to fully understand how Cisco Discovery Protocol operates, do the lab. 4.3.5-CDP Neighbors
Multiple Testing Methods For a basic introduction to router
troubleshooting, do the labs. 4.4.2-Remote telnet access 4.4.3-ICMP Ping 4.4.4-Traceroute command 4.4.7-Show interfaces & clear counters 4.5.1-Troubleshooting tools challenge
Active mental participation in answering lab questions is crucial to do well on the test.
You will also retain the knowledge longer if you think about what you are doing and why!