I have a linux box and a linux laptop, both have Fedora Core 2. My laptop also has winxp installed. When the box and the laptop are connected to my router things are fine.

I have two ethernet cards in the box. Eth1 is set to 192.168.0.14 and eth0 is set to 192.168.0.88. When both cards are connected to the router i can ping both addresses. When only one is connected i can ping that card's ip address and the same with the other card.

What I want to do is connect directly to the box from the laptop. I have an ethernet cable nearby. When I connect to the card and run 'ipconfig eth0 192.168.0.11 on' on my laptop, the card seems to be on. I can't ping anything; although I've checked the arp table and the ip address is in there, matched with the right mac address.

How do I ssh into the box? Am I doing something wrong?

You configured two interfaces in the same box for the same subnet, that is your problem. They have to be on separate subnets.

Ok, it works now.

I'm just wondering why there's that restriction. Is it possible to share data between the two subnets in some logical way? Is there any configuration which allows the laptop to be on the same subnet as the box?

You could setup proxy-arp, but that's rather ugly, messy, and completely unnecessary. What's wrong with being on separate subnets? They are, after all, on physically separate network segments.

I'm just wondering how you could put a server on one subnet and access it from another subnet. Is it as easy as a couple of route commands? I don't want anything like IP masquerading.

You would have to enter static routes at each end (i.e. the machines plugged into the machine in the middle--the one in the middle knows how to route the packets once it gets them, as long as you have IP forwarding turned on).