ip again

I HAVE TWO NETWORK SEGMENTS 150.150.1.* and 150.150.101.* i can ping both sides of them. i go into the network neighborhood of a system on the 1 segment and can see the individuals on the one but no the 101 and vis-versa. My question is what do i have to do to allow the 1.* and 101.* segements to see each other in the microsoft network neighborhood. Does igrp on a router have anything to do with it. Also what ports on the router need to be open for this to happen. What do i have to do on the stations or hardware routers to get this to work. we have a baynetworks router installed, do you know if ports 137 and 138 are enabled by default. Help
thanks for any help