Question : How to join two networks?

I have to separate networks that need to be joined together in a matter which allows:

1. All computers from Network B to access shared drives / files on network A
2. Network A must be a self contained domain
3. Network B can eihter be a domain or peer to peer network

A network map is available here: http://www.gogetmyfiles.com/netmap.pdf

We don't necessarily have to use a router, a linux box with two NICs is an available option.

Answer : How to join two networks?

Actually, I just don't see why you don't just add all the clients in Network B to the Network A Domain..  if you are going to share all 'Shares', then you need to have control, and that comes in the way of a Domain Controller and User Account Control..  the very best way to do what you are asking is by joining everything to the same Forest (and 2 separate SubDomains) or just one large Domain..  you can still segragate it with subnetting and the router if you wish..

FE