0P3N Blog Blog Post

CISCO Configuration Commands You Should Know

By: Humberto Hilario
April 6, 2016
CISCO Configuration Commands You Should Know - CybaryNavigation



Enter Privileged mode


Return to user mode from privileged


Access configuration mode

configure terminal

Exit Router

logout or exit or quit

Recall last command

up arrow or <Ctrl-P>

Recall next command

down arrow or <Ctrl-N>

Suspend or abort

<Shift> and  <Ctrl> and 6

Refresh screen output


Complete a command



Router Configuration



Set a console password to Cisco


This password is saved as clear-text within the config file

Router(config)#line con 0Router(config-line)#loginRouter(config-line)#password cisco

Set a remote access (telnet) password to Cisco


This password is saved as clear-text within the config file

Router(config)#line vty 0 4Router(config-line)#password cisco Router(config-line)#login

Stop console timing out

Router(config)#line con 0Router(config-line)#exec-timeout 0 0

Set the enable password to cisco


This password is saved as clear-text within the config file

Router(config)#enable password cisco

Set the enable secret password to peter.

This password overrides the enable password and is encypted within the config file

Router(config)#enable secret class

Protect clear-text passwords

Router(config)#service password-encryption


Router(config)#hostname Router2

Enable an interface

Router2(config-if)#no shutdown

To disable an interface


Set the clock rate for a router with a DCE cable to 64K

Router2(config-if)clock rate 64000

Set a logical bandwidth assignment of 64K to the serial interface

Router2(config-if)bandwidth 64

To add an IP address to a interface

Router2(config-if)#ip address

Static route the remote network is, with a mask of, the next hop is

Router2(config)#ip route

To enable RIP for network

Router2(config)#router ripRouter2(config-router)#network

Disable RIP

Router2(config)#no router rip

To enable EIRGP with a AS of 200, for network

Router2(config)#router eigrp 200Router2(config-router)#network

Disable EIGRP

Router2(config)#no router eigrp 200

To enable OSPF for backbone area (Area 0), for network 123 represents the process ID (PID).

Router2(config)#router ospf 123Router2(config-router)#network area 0

Disable OSPF

Router2(config)#no router opsf 123

Disable CDP for the whole router

Router2(config)#no cdp run

Enable CDP for he whole router

Router2(config)#cdp run

Disable CDP on an interface

Router2(config-if)#no cdp enable


Show Commands



View version information

show version

View current configuration (DRAM)

show running-config

View startup configuration (NVRAM)

show startup-config

Show IOS file and flash space

show flash

View the interface status of interface fa0/0

show interface fa0/0

Overview all interfaces on the router

show ip interfaces brief

View type of serial cable on s0/0

show controllers 0 (note the space between the 's' and the '0')

Display a summary of connected cdp devices

show cdp neighbor

Display current routing protocols

show ip protocols

Display IP routing table

show ip route

Display access lists, this includes the number of displayed matches

show access-lists

Configuration Management



Save the current configuration from DRAM to NVRAM

copy running-config startup-config

Merge NVRAM configuration to DRAM

copy startup-config running-config

Copy DRAM configuration to a TFTP server

copy runing-config tftp

Merge TFTP configuration with current router configuration held in DRAM

copy tftp runing-config

Backup the IOS onto a TFTP server

copy flash tftp

Upgrade the router IOS from a TFTP server

copy tftp flash


Debug and Troubleshooting



Enable debug for RIP/OSPF

debug ip rip or debug ip ospf

Enable summary EIGRP debug information

debug ip igrp events

Enable detailed EIGRP debug information

debug ip eigrp transactions

Enable debug for CHAP or PAP

debug ppp authentication

Switch all debugging off

no debug all

undebug all


~ Hope this is useful to you ~

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