I am well aware that Multi-home DC's are not "fully supported" in a Server 2008 environment but is possible. I am in the process of configuring two multi-home DC's because I am at a point where we have no choice due to a firewall/captive portal. This was our previous post enter link description here
We decided to use two secondary NIC's on both of our DC's so that our third DC, which is at our branch office can communicate with the home DC's bypassing the firewall. Can Server 2008 be configured so that replication can occur between domain controllers through the secondary NIC while network workstations can continue as normal by using the first configured NIC? Because at this time, within Active Directory Sites, when configuring the DC's with the secondary IP on NIC #2, the servers still cannot communicate with each other.