Windows Server 2003 DNS Forward Lookup Fails Reverse Look Up Succeeds

If you are trying to set an MX record for a hostname such as corp.example.com (for mail to user@corp.example.com) and that name exists as a CNAME record instead of an A record, it would result in this error. If a host exists as a CNAME, it cannot also have other record types associated with it. You would need to re-create the hostname as an A record and then add the MX record to it.

Create the CNAME record "portal.domain.com" referring to "obscureServer32324name.domain.com" in the "domain.com" DNS zone. From a command-prompt, do a:

nslookup portal.domain.com

What do you get back?

Bear in mind that if "domain.com" is an Active Directory-integrated zone you could have a slight delay before the DNS server begins to resolve it.

Also on the Active Directory integrated DNS front, bear in mind that your DNS client might not be trying to resolve against a DNS server that's "looking at" the same copy of AD where you added the record (via DNSMGMT) a moment before. Force AD replication or wait 5 minutes for AD replication to complete.

You don't need to stop / restart the Microsoft DNS server for changes like this to "take".

Edit re: your comments:

Bizarre. I'm at a bit of a loss. That's a pretty common configuration, so it ought to work fine. I have several Customers with servers that are configured just that way (w/ CNAME records like "WSUS" or "antivirus", etc).

The computer you're testing from is configured to use the server computer where you added the CNAME as its DNS server-- correct?

Do the following, just be sure that you're querying out of the right zone:

nslookup -querytype=SOA domain.com

You should get back something like this:

domain.com
        primary name server = server.domain.com
        responsible mail addr = hostmaster
        serial  = 425
        refresh = 900 (15 mins)
        retry   = 600 (10 mins)
        expire  = 86400 (1 day)
        default TTL = 3600 (1 hour)
server.domain.com     internet address = 192.168.1.1

Be sure the SOA record that you get back really is referring to the server computer you expect to be seeing the zone hosted from.

We'll figure it out, it just may take a moment.