Default interface configuration command

 

The easiest way to remove all settings from an interface is to use the default interface configuration command. For example, if you've configured Frame Relay interface with subinterfaces ...

interface Serial0/0/0
 no ip address
 encapsulation frame-relay
 load-interval 60
!
interface Serial0/0/0.100 point-to-point
 bandwidth 2000
 ip address 172.16.1.1 255.255.255.252
 ip load-sharing per-packet
 ip ospf cost 50
 frame-relay interface-dlci 100

... and have erase all interface-specific configuration, the ...

rtr(config)#default interface serial 0/0/0
Building configuration...

Interface Serial0/0/0 set to default configuration

... gets you there. As you can see, after the configuration change, the main interface has no IP address and the subinterface is deleted.

a1#show ip interfaces brief
Interface          IP-Address  OK? Method Status     Protocol

... non-relevant lines deleted ...

Serial0/0/0        unassigned  YES TFTP   up         up
Serial0/0/0.100    unassigned  YES manual deleted    down