Two CNAME records being resolved differently (Windows 2003 Server)

Solution 1:

Server 2003 DNS has been around a while, I kind of doubt there's an incompatibility but I guess it's possible. If there is one it's not an OS issue but an MS DNS <--> "Other DNS" server issue. The DNS server doesn't know/care about the OS of the requestor or the DNS server it's querying.

I think you're going to have to look at the DNS logs from your server and see if your ISP can review them with you and/or look at their own logs to see what they are returning to DNS queries for your domain.

Make sure you disable EDNS on the W2k3 box. http://support.microsoft.com/kb/832223

I have seen a DNS server not resolve when DNS others do and usually it's a forwarding issue. In this case I do not have fwder's on my DNS and it fails for me but works when I change to an ISP's DNS server nearby. I would remove any forwarders if you have them setup on the DNS server in any case.

I tested from the US using my internal MS Server 2008 DNS, it fails consistently but with 2 different results:

mail.wilmot.me.uk
Server: [10.10.254.11]
Address: 10.10.254.11
*** [10.10.254.11] can't find mail.wilmot.me.uk: Non-existent domain

mail.wilmot.me.uk
Server: [10.10.254.11]
Address: 10.10.254.11
*** [10.10.254.11] can't find mail.wilmot.me.uk: Server failed

Google DNS server resolves it fine:

mail.wilmot.me.uk
Server: google-public-dns-a.google.com
Address: 8.8.8.8
Non-authoritative answer:
Name: wilmot.me.uk.mail.aaisp.net.uk
Addresses: 2001:8b0:0:30:230:48ff:fedb:256a
2001:8b0:0:30:230:48ff:fedb:25dc
81.187.30.14
81.187.30.19
Aliases: mail.wilmot.me.uk

Finally from a client's internal MS Server 2003 DNS I also got NXDomain:

mail.wilmot.me.uk
Server: oddjob.xyzassociates.com
Address: 192.168.2.7

*** oddjob.xyzassociates.com can't find mail.wilmot.me.uk: Non-existent domain

Hope that helps out a bit.

Solution 2:

Worked for me no problem on OS X 10.6:

bash-3.2$ dig mail.wilmot.me.uk

; <<>> DiG 9.6.0-APPLE-P2 <<>> mail.wilmot.me.uk
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 23413
;; flags: qr aa rd ra; QUERY: 1, ANSWER: 3, AUTHORITY: 2, ADDITIONAL: 2

;; QUESTION SECTION:
;mail.wilmot.me.uk.     IN  A

;; ANSWER SECTION:
mail.wilmot.me.uk.  0   IN  CNAME   wilmot.me.uk.mail.aaisp.net.uk.
wilmot.me.uk.mail.aaisp.net.uk. 3471 IN A   81.187.30.14
wilmot.me.uk.mail.aaisp.net.uk. 3471 IN A   81.187.30.19

;; AUTHORITY SECTION:
mail.aaisp.net.uk.  3368    IN  NS  auth.primary-dns.co.uk.
mail.aaisp.net.uk.  3368    IN  NS  auth.secondary-dns.co.uk.

;; ADDITIONAL SECTION:
auth.primary-dns.co.uk. 3466    IN  A   81.187.30.42
auth.secondary-dns.co.uk. 3466  IN  A   81.187.81.33

;; Query time: 158 msec
;; SERVER: 10.6.18.110#53(10.6.18.110)
;; WHEN: Wed Feb 24 09:18:45 2010
;; MSG SIZE  rcvd: 225

bash-3.2$ dig mail2.wilmot.me.uk

; <<>> DiG 9.6.0-APPLE-P2 <<>> mail2.wilmot.me.uk
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 41203
;; flags: qr aa rd ra; QUERY: 1, ANSWER: 3, AUTHORITY: 2, ADDITIONAL: 2

;; QUESTION SECTION:
;mail2.wilmot.me.uk.        IN  A

;; ANSWER SECTION:
mail2.wilmot.me.uk. 0   IN  CNAME   C.mail.aaisp.net.uk.
C.mail.aaisp.net.uk.    3357    IN  A   81.187.30.19
C.mail.aaisp.net.uk.    3357    IN  A   81.187.30.14

;; AUTHORITY SECTION:
ail.aaisp.net.uk.   3357    IN  NS  auth.primary-dns.co.uk.
mail.aaisp.net.uk.  3357    IN  NS  auth.secondary-dns.co.uk.

;; ADDITIONAL SECTION:
auth.primary-dns.co.uk. 3455    IN  A   81.187.30.42
auth.secondary-dns.co.uk. 3455  IN  A   81.187.81.33

;; Query time: 162 msec
;; SERVER: 10.6.18.110#53(10.6.18.110)
;; WHEN: Wed Feb 24 09:18:56 2010
;; MSG SIZE  rcvd: 216