Networking problem

[Tkachenko, Artem N]

Hi,

I posted similar question some time ago but I guess I misstated the problem.
I will be more careful this time. Here is my situation:

Node A <-----> LAN1 <-----> Node B <-----> LAN2 <-----> Node C
 
Node A:
OS: Win2K
IP Address (to LAN1): 129.197.23.232

Node B:
OS: FreeBSD 4.6
IP address (to LAN1): 129.197.244.10
IP address (to LAN2): 10.77.1.1

Node C:
OS: FreeBSD 4.6
IP address (to LAN2) 10.77.2.1

What I am trying to accomplish is to set up Node A and Node B (and not Node
C) to have Node A think that it is directly connected to LAN2 with an IP
Address 10.77.1.2

So if Node A needs to send a packet to Node C, some program on Node A will
encapsulate the packed and send it to Node B. Some other program on Node B
will get the encapsulated packet, recognize that it came from Node A and
that it needs to go somewhere else on LAN2, open the capsule and forward the
original packet to the appropriate destination.

And if Node C needs to send a packet to 10.77.1.2, the router on LAN2 will
force it to send the packet to Node B. The Node B should then forward the
packet to Node A.

I tried to accomplish this in many ways but was not able to get exactly what
I was looking for. I would highly appreciate if someone could tell me which
program I need to use. ANY help if highly appreciated. I am really stuck...
Thank you in advance. Sincerely

Artem