2nd Ethernet Bogosity

[Gary Trimble]

We have a Sun 3/260 which was bought with a (factory installed) 2nd
Ethernet Card which we want to use as a gateway (what else?). When I
installed the 4.0.3 O.S. I set the addresses and data "by the book".  Now,
when the second enet controller (ie1) is off (not turned on by the
rc.local currently) the primary net works fine. When I turn on the gateway
net card (ifconfig ie1 ego-gw -trailers up) the local net stops and the
other net is reachable. Perhaps I don't understand the use of the netmasks
and relationships to yellow pages correctly. Could any successful gateways
implemeentors please suggest hints? Thanks

Gary Trimble