Is it possible to forward a connection to a port to a completely unrelated external address? For example, I want to redirect ssh traffic to a.b.c.d to w.x.y.z. If w.x.y.z were an internal address and the machine was the router, this would just be plain old NAT port forwarding. But what if w.x.y.z is not an internal address?

The reason I want to do this is I want to reassign a domain name example.com from ip address A to B, while allowing users to still ssh into A by using the example.com domain name. Is this unreasonable?*

(I am guessing it is unreasonable, since the A wouldn't have it's gateway set to B, as is the case if A were in B's NAT'd internal network.)

Smarter ideas highly welcomed.

wait... I can do this with netcat/socat, can't I?

If you are using IPTables it is quite simple. Just set up a rule which DNATs port 22 to A and port 80 to B. AFAIK it doesn't matter that the IP address is external. The output mangling is the last chain, so if you redirect to an outside address the traffic is NATted (Masqueraded) just like any internal traffic going to the outside.

jlinkels