How to assign IPs according to router IP?

[Simon Hobson]

Robinson Tiemuqinke wrote:

>  I've heard there is a way to assgin a same box (same
>MAC address and same OS) different IPs according to
>where(which networks) the dhcp request is sent from.
>But I just can not find it now. Any one have the idea
>how to fulfill it? It looks like some kind of "if ...
>then ..." statements.

Sigh ! RTFM !

This is automagic, you do not need to configure anything, the server 
automatically picks up the relay agent address (GIAddr) and selects 
the appropriate subnet. All you have to do is correctly configure a 
relay agent on each subnet that is not directly attached to the 
server - and while it is customary for this to be done in the router, 
it can be done in any device attached to the remote network.