index

An arbitrary index for the unnumbered interface configuration

1-255

interface-type

The interface type of the interface from which to borrow an IP address

FastEthernet

Serial

Vlan

Loopback

Tunnel

Dialer

identifier

The identifier depends on the interface type:

For FastEthernet: module/port

For Serial: module/port:channel-group [.sub-interface]

For Vlan: vlan-id

For loopback: loopback number

For Tunnel: tunnel number

For Dialer: dialer number

For FastEthernet: 10/3 or 10/4

For Serial: 3/1, 4/1, 8/1

channel-group: E1: 0-30, T1: 0-23

For VLAN: 1-4090

For Loopback: 1-99

For Tunnel: 1-50

For Dialer: 1