Windows® Essential Business Server 2008 Administrator's Companion

Task 4: Configure Subnets

You can expect configuring subnets to take less than 15 minutes. Forefront TMG, the firewall application that runs on the Security Server, needs to differentiate between external and internal networks so that traffic can be properly routed between these two networks. However, Forefront TMG detects only one internal subnet—the one to which it is directly attached. Therefore, if you have a routed network with multiple internal subnets, you need to register in Forefront TMG all the internal subnets that are not directly attached to the Security Server.

Important

You must not register any subnets found in front of the Security Server, such as one you would find between the Security Server and a preexisting firewall device you ...