Most Used Cisco IOS Commands.23057.45282

8/3/2019 Most Used Cisco IOS Commands.23057.45282

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D&T team Author : Dimitar Krstevski

Most used Cisco IOS commands

Cisco IOS is one big operating system and has a lots of commands. Depending on the IOS version notall commands are available in all Cisco IOS versions. In this document we will show the mostly used

Cisco IOS commands that every network administrator should know and use in everyday situations.

Router Modes

Mode Description

Router> User mode

Router# Privileged mode

Router(config)# Global configuration mode

Router(config-if)# Interface mode

Router(config-subif)# Subinterface mode

Router(config-line)# Line modeRouter(config-router)# Router configuration mode

Router(config-if)#exitRouter(config)#

Exit interface mode, return you one mode before

Router(config-if)#end Router#Exit interfacemode, return to global configurationmode, (CTRL+Z)

Global Configuration Mode

Command Description

Router> Can see config but not change

Router# Can see config, and move to make changes

Router# conf t Router(config)# Moves to global config mode

Router(config)#no ip domain-lookupDisable IP domain name system hostnametranslation

Router(config)#banner motd^Hello^ Sets Hello like message of the day banner

Configure Router Name

Command Description

Router(config)#hostname vtyme Name can be any word you choosevtyme(config)# After change was made


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Configure Passwords

Command Description

Router(config)#enable passwordcisco Set enable password

Router(config)#enable secret class Set enable secret password

Router(config)#line con 0

Router(config-line)#passwordconsole

Router(config-line)#login

Router(config-line)#loggin synchronous

Enter console line mode, sets console-line mode password to console, enablepassword checking at login and enablesynchronized message output

Router(config)#line vty 0 4

Router(config-line)#passwordtelnet


Router(config-line)#loggin synchronous

Enter vty mode for all 5 vty lines, setsvty password to telnet, enablepassword checking at login and enablesynchronized message output

Router(config)#line aux 0

Router(config-line)#passwordnopass


Enters auxiliary line mode, sets auxiliaryline mode password to nopass, enablepassword checking at login

Router(config)#service password-encryptionApplies a weak encryption to passwords


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Show Commands

Command Description

Router#show startup-config Displays configuration saved in NVRAM

Router#show running-config Displays condiguration currently running in RAM

Router#show protocols Displays status of configured Layer 3 protocols

Router#show ip route Displays routing table

Router#show ip protocolsDisplays IP routing protocols process parameters andstatistic

Router#show vlan Displays VLAN status

Router#show vtp Displays VTP information

Router#show spanning-tree Displays spanning tree topology

Router#show mac-address-table Displays MAC table

Router#show ip interface brief Displays summary of interface IP status andconfiguration

Router#show cdp neghbors Displays neighbor entries

Router#show arp Displays the ARP table

Router#show version Displays info about loaded software version

Router#show flash Displays info about Flash memory

Router#show history Displays history of commands used

Router#show users Displays all users connected to device

Router#show clock Displays time set on device

Router#show controllers serial 0

Displays statistics for interface hardware. Statisticsdisplay if the clock rate is set and if the cable is DCEor DTE or not attached

Router#show sessions Displays all telnet connections to device

Saving Configuration

Command Description

Router#copy run startSaves the running-config to local NVRAM

Router#copy run tftp Saves the running-config remotely to TFTP server


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Configure Interface

Command Description

Router(config)#interface fa0/0

Moves to FastEthernet 0/0 interface

mode

Router(config-if)#ip address 192.168.1.2 255.255.255.0

Assigns address andsubnet maks tointerface

Router(config-if)#no shutdown Turn interface on

Router(config-if)#description homeLan

Optional description ofthe link is locallysignificant

Router(config-if)#no ip addressRemove assignaddress from interface

Router(config)#interface s0/0Moves to Serial 0/0

interface mode

Router(config-if)#clock rate 64000 Configure serialinterface clock speed

Documents

Most Used Cisco IOS Commands.23057.45282