[lug] Two NICs, one IP

[Jeff Schroeder]

Hey all--

I manage a Linux server for a client, and he has asked me to set things 
up so the server will be able to withstand the failure of a physical 
cable on the LAN.  The server has two NICs (eth0 and eth1, in 
Linuxspeak) and he wants both to have the same IP address.

I don't believe this is possible, since the box won't know where to 
route outgoing packets (eth0? eth1? both?), and I've seen instances 
where a network interface won't even come up if the system thinks 
there's another machine with that IP on the network.

However, before I tell him it isn't possible, I wanted to confirm it 
with the group here.  I don't have any hard-and-fast documentation to 
support my claim, but it just doesn't seem right to me.  Can anyone 
tell me for sure that it's not possible?  Or, if it is, how to do it 
properly?

TIA,
Jeff