2

I created a subdomain, but the connection just times out. I checked the zone file and I have one (A)ddress record with a wild card (*) pointing to my server's IP address. As far as I understand, that's the correct setting in the zone file to make sure all subdomains point to my server. Is there something else I am missing? What are ways to troubleshoot this issue?

I have used trace route, ping, and dig to find out more information.

ping -> timeout (loss)
trace route -> no conclusion
dig -> tells me that the domain does have an address
  • Can you ping the IP address as expected? As well, if you cannot ping you cannot trace route since trace route uses ping. Does nslookup resolve the sub-domain name? It is okay to use an IP address for a sub-domain, but if your parent domain works, I recommend using CNAME and pointing your sub-domain to your parent. Some DNS servers do not like using A records for sub-domains and some do not like using CNAME records. They are few and far in between, but they exist. – closetnoc Oct 17 '14 at 16:13
  • I get a timeout when I ping the subdomain. The DNS lookup points to my server IP. – gdaniel Oct 17 '14 at 16:26
  • I get that. Does your parent domain name work? Try using a CNAME record instead of an A record. This may solve your problem. But make sure your parent domain works first. – closetnoc Oct 17 '14 at 16:29
  • The parent name works. I will try using a cname instead. Thanks. – gdaniel Oct 17 '14 at 17:04
  • Let us know if that works. I used to be a web host and a network engineer for about 30 years. I know that sometimes A records do not work for sub-domains in some DNS servers or even the other way around. Traditionally, A CNAME is the thing to use which is one reason why I recommended it. Generally I suggest using a CNAME first unless that does not work for some reason. Then drop back and punt to an A record. – closetnoc Oct 17 '14 at 17:27
1

The exact rules for when a wild card is match are specified in RFC 1034, but the rules are neither intuitive nor clearly specified. This has resulted in incompatible implementations and unexpected results when they are used.

Your DNS should look like this

  1. A NAME (blank or @ on some systems) FQDN domain.com IP
  2. A NAME www FQDN www.domain.com IP
  3. A NAME subdomain FQDN subdomain.domain.com IP

Try and avoid a wild-card in the DNS.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.