Default Interface

[Bulent Murtezaoglu <bm@acm.org>]

    RB> ...Is there a way, when I talk
    RB> to the outside world across my WAN card, to make it use the ip
    RB> address of my ethernet card.  

[I am assuming that your ethernet card is also connected to the
Internet]

This will work OK if the upstream from your wan card will route 
packets originating from you with a foreign address.  Out of the box
Cisco's will, but they can also be set up to block this.

    RB> In other words, when I telnet,
    RB> ssh, ftp to a box on the outside world, I want it to show up
    RB> as a connection from mail.mynetwork.com (my ethernet address)
    RB> and not host_on.framerelaycloud.provider.com (my wan address).

For _server_ stuff I'd just set the IP address the listening sockets
binds to the address you want and have the dafult route point to
the next-hop from the WAN card.  Your problem is not that though --
for clients you either have  to force them to use the interface you
want (a cursory look at the ssh man page reavealed no such option) 
or use "policy routing."  What you want to accomplish is setting 
next-hops based on the destination port of the TCP segment contained
in the IP packets.  iproute2 should be able to do this for you but
I cannot tell you how to get it to do it.  

I'd be interested to find out if I'm missing anything on this.

cheers,

BM