KB

CISCO

Basic Commands

When typing any command, you can press <?> to show help information. This can show available commands, and also syntax for specific commands. You can also use <TAB> to complete commands.

  • Clear the NAT translation tables: clear ip nat translation *
  • Go to beginning of line: CTRL+A, to end of line: CTRL+E 
  • Delete the startup config (will show setup mode after reload): erase startup-config
  • Show host table: show hosts (temp = cached lookup, perm = host added with "ip host")
  • Disable console logging: no logging console
  • Turn off all debugging: undebug all or un all

Reload the Router

  • Reload config: reload
  • reload in 5 (say no to save config)
  • reload at
  • reload cancel
  • Some examples: http://www.problutions.com/?p=462

Show the Running Config

  • Turn off the annoying MORE behaviour: terminal length 0 (term len 0)
  • Show the configuration: show running-config (show run)
  • Show the startup config: show startup-config (show start)
  • Revert changes from startup config: copy startup-config running-config (copy start run) - or just reboot the router
  • Commit changes to startup config: copy running-config startup-config (copy run start)
  • Another method (does the same thing): wr
  • Start displaying config at specific line containing <word>: show run | begin <word>
  • Display all lines with given <word>: show run | include <word>
  • show run | section <word>

Routing

  • Show routes: show ip route

Interfaces

  • List interfaces: show ip int brief
  • Show particular interface: show run interface Dialer0

Insert ACLs using Line Numbers

  • To show ACL rules with line numbers: show ip access-list
  • To remove a line (eg. 50): no 50
  • To add a rule at a line number (eg. 50): 50 permit udp any any eq domain

Cisco Catalyst Switches