Hi there,
We have a scenario where 3 (three) multiple external Internet connections are connected directly to our TMG with publicly subnetted address ranges on separate NICs and connected to separate routers.
The configuration is 1 x ADSL2 connection (which is the only connection configured on TMG with a default gateway), and 1 x 4Mbit SHDSL and 1 x 2Mbit SHDSL. We also have one internal NIC and a perimeter NIC.
I am attempting to implement server publishing rules on the 4Mbit and 2Mbit services but all of the outgoing traffic appears to return or be limited by the bandwidth of the default gateway's connection. I've tried creating NAT Network Rules to services to encourage the return traffic back through the NIC it originated on but it seems that everything which exits the network to the Internet through TMG, regardless of any server publishing rules, ends up going out the default gateway. For example, ingress traffic with any publishing rule on the 4Mbit service comes in through the 4Mbit service, but appears to send all of its egress traffic through the ADSL2 connection, rather than returning in a stately fashion to the incoming IP address on the 4Mbit NIC. (This doesn't make a lot of sense to me routing-wise but it's what I'm seeing through NIC traffic and packet captures).
Is this configuration something which is supported on TMG? - Multiple WAN links with specific publishing rules on each NIC, expecting traffic to exit on the same NIC that it enters? Does it require further configuration? Or does TMG just not work like this?
I have tested extensively and happy to provide further detailed information.
Thanks, Tim.