Semester 2 - Review

Router Commands

Show

version - IOS that is running, file that is loaded, config reg

processes - active processes

protocols - status of Layer 3 protocols running

mem - stats about routers memory

stacks - monitor processes, interrupts and reason for last reboot

buffers - stats for buffer pools

flash - info on flash memory

running-config - displays active config file

startup-config - displays booted or backup config

interfaces - stats for all interfaces on router

serial - list all serial interfaces only
ethernet - list all ethernet interfaces only

cdp - info on directly connected routers

neighbors - device ID, local port type and number, capability code, hardware platform, remote port type and number
interfaces - shows timers, interface status, encapsulation
entry {device name} - show layer 3 info for a specific router, IOS version, platform

reload

reboots the box. performs all tests

setup

from Privileged EXEC mode, enters initial setup configuration, starts over

configure terminal

configures manually from the console terminal.

show startup-config(write mem)

displays the saved configuration, which is the contents of NVRAM.

show running-config(write term)

displays the current configuration in RAM.

configure memory

loads configuration information from NVRAM.

copy running-config startup-config

stores the current configuration from RAM into NVRAM.

copy tftp running-config

loads configuration information from a network TFTP server.

copy running-config tftp

stores the current configuration from RAM on a network TFTP server.

erase startup-config(write erase)

erases the contents of NVRAM.

Boot sequence

What steps does the router go through to boot?

It tests all hardware, loads IOS software, loads configuration file

Bootstrap - preset operation that loads instructions that cause other instructions to be loaded into memory

This loads from ROM

IOS - Operating software. this tells the box what interfaces it has and what protocols to run

Configuration File

Click here to see a flow chart of the boot sequence.

Router> - user EXEC mode

Router# - priviledged EXEC mode

Router(config)# - global config mode

Router(config-if)# - specific interface mode(serial 0/ethernet 1)

Router(config-line)# - specific line mode (console/vty)

Router(config-router)# - routing protocol mode

Config registers

0x2100 - Boot into ROM monitor mode
0x2101 - Boot from ROM (Limited IOS) Default if no flash
0x2102 - Looks in NVRAM first for boot-system commands. If none then boot from flash

For a complete list of config registers click here

Naming conventions

C2500-d-l

2500 series box, d - router ip/ipx features, l - not compressed/relocatable

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