Forefront TMG Default Gateway

[teejay]

Ok, think my brain is in stupid mode today. Used linux based firewall before, not ISA or Forefront.
I'm trying to set up a test network with Forfront TMG, I want the FOrefront TMG box to be the default gateway for the network, but when I try to set this in the ip address of the Forefront box as the default gateway in the configuration wizard on the local LAN it tells me its an invalid default gateway.
How would I configure this?

[SYNACK]

Um if I understand correctly you've muddled the config a little. The Forfront box should have a default gateway outside your network to your IPS or upstream connection so that it itself can communicate with the outside world and direct traffic. If you want the clients to look to it as their default gateway you should change this in DHCP so the clients know to look to the TMG box for outside access and the TMG box then hands the outside traffic up to its default gateway which is probably your ISP.

[teejay]

Have

Internet - NIC1 (extenal IP) -Forefront Box - NIC2 network 192.168.0.1

In the TMG configuration wizard when you set the internal network IP on NIC2 it asks for a default gateway. It will only accept an IP address in the internal network range and will not accept the IP address you set for the internal nic as the defauilt gateway. The internal network machines would want the TMG machine as their default gateway as its the route out to the internet.

[SYNACK]

Odd there should be no internal default gateway set as the TMG is the border device. It should be left blank.

[teejay]

Thanks
Told you my brain was in stupid mode today