I have 3 computers; A,B,and C. All are running Win98SE.
A&C are connected through a DSL Router, with an Ethernet cable and an Adapter Card  in each computer (not  USB). B is connected to A with an Ethernet cable and a 2ND adapter card in A , and one in B.
The network is known to A  as consisting of B & C; but from B only A is known, and from C only A is known
I can share files, etc, from A with both B & C. I can share files from C only with A. I can share files from B only with A
How do I make C aware of B, and B aware of C?
I don't believe this is a firewall problem.
TomNo it is not a firewall problem.  Basically your A computer is acting as a router(not a hub) and SINCE you have given it no additional information it keeps the 2 networks seperate.

Now on NT Server etc, you can set it up to pass through the computer.  I don't know of a way to do that on 98 as it was never intended as a server.  

Probably the easiest and least frustrating solution would be to purchase an inexpensive hub at your local computer store (some are less than $20.00) and plug them all into the hub which should plug into your DSL router.

Other than that we are talking about static IP addresses with multiple static routes and multiple gateways which can GET troublesome on 98.Connect everything through the router then use NETBUI for file and print sharing.Gussery's reply was about what I expected. I thought it was worth it to ask the question, though.
Because of geographical limitations, 2K DUMMY's solution is not practicable, though I'm sure it would work.
Thanks for the ideas.
Tom