Gateway IP change, now no routing

Hi,

Will appreciate some pointers and help with this situation.

Win2003 Std server in the role of Domain Controller. It had a gateway (router) on IP 10.0.6.5 and I have now added a physical gateway (DSL router) on IP 10.0.6.254. Changed the obvious Network Configurations giving it the new gateway IP and also that as DNS server (with some upstream servers too).

My problem: I can not ping or trace to the new gateway on .254. Rebooted the server and the router.

What I've done:

1) Checked the DHCP scope, 254 is avalable to be allocated, so I created a Excluded Range. Still no change.

2) Changed gateway IP from 254 to 10, did not help

3) Checked hosts file, nothing funny in there

4) Checked ROUTE cmd, no custom routes.

Did get it once to ping the gate on 254, lasted about 3 minutes, then the gateway just "went away"

What boggles me, is the rest of the network can see the router and get onto the internet fine. Its just the DomCntrl that's giving this issue. What can keep ot from 'seeing' 254?

Any pointers or help with this?

Appreciated!!!