At our school we have a remote building linked by a wireless bridge. Performance was poor, so I added a local DC to serve this building. The wireless bridge requires that both ends be in the same subnet. Some things still get serviced from the main servers across the slow link occasionally. I need to separate the building into a separate subnet. I have installed a 2nd NIC in the server. The NIC pointing at the bridge is 10.66.16.21/24 and the one to the LAN is 10.66.18.2/24.
The local DHCP allocates addresses in 10.66.18.0/24 with default gateway as itself, 10.66.18.2. From the server, I can ping the main site, and connect to the internet via the main site gateway. I can also connect to the local PCs. I turned on RRAS and added 0.0.0.0/0 gateway 10.66.16.21 to the bridge interface, and 10.66.18.0/24 gw 10.66.18.2 to the LAN interface. The local PCs can see the local server, but not the main network. What am I doing wrong? The router just isn't routing! How do I break down the problem to test it? Are there test programs to run?