Using Aliases in Cisco Routers

Cisco has long, frequently used commands like our favorites "show ip interface brief", "show ip route" and the annoying "do show" commands while in the global configuration mode. If you want the easy way, the good news is there is an easy way. Using aliases will save you some keystrokes. Here's the way to configure aliases. We will create aliases for the commands above and also be able to use the "show" command on the global configuration mode. "show ip interface brief" will be assigned with the alias "sib", "show ip route" will be "sir" and "do show" will be "show".

Router(config)#alias exec sib show ip interface brief
Router(config)#alias exec sir show ip route
Router(config)#alias configure show do show

Let's test if the alias commands really work.

Router#sib
Interface                  IP-Address      OK? Method Status                Protocol
FastEthernet0/0            unassigned      YES unset  administratively down down

Router#sir
Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP
  D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
  N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
  E1 - OSPF external type 1, E2 - OSPF external type 2
  i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2
  ia - IS-IS inter area, * - candidate default, U - per-user static route
  o - ODR, P - periodic downloaded static route

Gateway of last resort is not set

Router#config t
Enter configuration commands, one per line.  End with CNTL/Z.
Router(config)#show ip int brief
Interface                  IP-Address      OK? Method Status                Protocol

FastEthernet0/0            unassigned      YES unset  administratively down down

Well it did! Lets check what we will see in IOS help.

Router#s?
*s=show     *sib="show ip interface brief"  *sir="show ip route"  sdlc
send        set                             setup                 show
slip        snasw                           squeeze               ssh
start-chat  systat

Router#config t
Enter configuration commands, one per line.  End with CNTL/Z.
Router(config)#s?
*show="do show"  sap-priority-list  scheduler          scripting
secure           security           service            sgbp
signaling-class  sip-ua             sna                snasw
snmp             snmp-server        source-bridge      srcp
standby          state-machine      stun               su-mac
su-tag           subscriber         subscriber-policy  subscription

Now we see the aliases we made and they have the preceeding asterisk before them. *s=show is the default alias in the router. Cool! Try other aliases in different modes, make your own aliases and just be creative!