I have a routing problem that I need to solve for both Windows and Linux.

In our test lab, I've set up a small network that is separated from the rest of the work by a firewall. One interface is on the 15.8.152 network, the other is on the 192.168.100 network.

I can already get to the 192.168.100 network from the 15.8.152 network, by virtual of the fact that one interface of the firewall is on that network.

I need to get to the 192.168.100 network from the 15.255.16 network. I do not have access to change any router configs on the 15.255.16.1 or 15.8.152.1 routers.

From a 15.155.16 system, I tried route add -net 192.168.100.0 netmask 255.255.255.0 gw 15.8.158.152 dev eth0 which gives me SIOCADDRT: Network is unreachable - I get a similar error when attempting to do this from a Windows box.

What I need to do is construct one or more "route add" commands to build the route, but I'm stumped.

Alternately, I have another linux box which has a interfaces on both the 15.255.16 and 15.8.152 networks - I imagine I could turn it into an alternative router to bybass the 15.255.16.1 and 15.8.152.1 routers.

Thoughts?