[c-nsp] Same IP on two interfaces?

[Alex]

> The scenario is the following: router is connected via Fa0/0 to sw0, and 
> via
> Fa0/1 to sw1 (sw0 and sw1 are interconnected).
>
>
>
> IP X.Y.Z.100 should belong to both interfaces: if sw0 or sw1 fails, router
> should still be reachable.
!
interface Loopback100
ip address 10.1.1.1 255.255.255.0
!
interface FastEthernet0/0
ip unnumbered Loopback0
!
interface FastEthernet0/1
ip unnumbered Loopback0
!
Does it solve Your problem?
HTH
Cheers
Alex