Hi all,
We promoted a new domain controller to the domain recently. The next day, we had a call to say the internet was down on site. This turned out to be due to a DNS problem when client browsers were trying to resolve our WPAD servers to get the auto-discovery info for our proxy.
We have a static DNS entry for "wpad" in each domain within the forest, which points to the domain's respective WPAD hosting servers (just a plain old webserver hosting various wpad.dat files). After promotion, we configured DHCP to use the new server as its primary DNS. Almost everything works fine, except this one single DNS entry. For some reason, it resolves "wpad" to the wrong domain - consequently this breaks web browsing, since the server its directing wpad requests to does not host the exact file name our clients are configured to use.
This led me to check the DNS config. Just some clarification here, our domain is 'emea.lendlease.com', which is a domain within the forest 'lendlease.com', so we should expect to see wpad resolve to wpad.emea.lendlease.com when doing an nslookup.
This doesnt happen.
Instead, quite randomly, when using this new DC as DNS, it resolves 'wpad' to 'wpad.amer.lendlease.com' which is the wrong domain (see attached nslookup image). The correct server this should resolve to is 172.17.25.25 and .26, as per the result from our
Primary DC.
And below is the DNS search suffix order:
This all correct, and is an identical config to our other DC's that do not have this issue.
Anyone have any ideas? Is there some hidden settings I should be looking at here?
Thanks.