We've got a Windows 2008 R2 MDT server that's multihomed on our 100MBit external network (which can see the interwebs) and a 1GBit internal network (for testing, etc, with NATed interwebs access). We have PXE enabled and working fine on the internal network, but we're having a little problem. Currently, after a client machine on the internal network PXE boots and starts talking to the server to get the Windows install image, etc, it ends up chatting with the server via it's external interface which is drastically slower than the internal interface. Our previous MDT server wasn't doing this, but I believe that was due to sheer luck.
Anyone know what we need to do (or where we need to start looking) to get any communications started on the internal network to stay on the internal network?