4 Replies Latest reply: Jul 12, 2013 9:31 PM by edit6969
edit6969 Level 1 Level 1 (0 points)

Hi all, first time post, we have a strange DNS setting issue. Extenaly our website resolves fine. Internaly however, only "www.example.com" resolves. "http://example.com" and just "example.com" dont work but they do externaly. What DNS settings should I use to resolve this?

 

MAC OSX Sever 10.6.8, Xserve

 

Many Thanks

 

Mike


Mac OSX server 10.6.8, OS X Server
  • 1. Re: Internal dns settings
    Camelot Level 8 Level 8 (45,790 points)

    First off, you need to understand that there is no automatic relationship between 'example.com' and 'www.example.com'.

     

    'www.example.com' is just a hostname within the 'example.com' domain, and is no different from any other hostname such as 'mail.example.com', 'foo.example.com', etc.

     

    Now, by convention/convenience most people map 'example.com' and 'www.example.com' to the same IP address so that (lazy?) users can type the former into a browser and get to the web site, but that's not an automatic thing.

     

    In this case, since it works externally but not internally, it sounds like you're using two different DNS servers (one for public users and a different one for private/LAN users) - which is a good idea. It just means that the internal DNS doesn't have the same configuration that maps 'example.com' to the address of your web server.

     

    As for the fix - make sure that 'example.com.' has an A record that points to your web server's address.

  • 2. Re: Internal dns settings
    MrHoffman Level 6 Level 6 (12,465 points)

    FWIW, it'll usually want to be a DNS CNAME (alias) and not an DNS A (machine) record that gets added.

     

    DNS A records are expected to work the same for both forward and reverse DNS translations — DNS host name to IP address as the forward, and IP address to name as the reverse — and — given you're aliasing the host — that isn't and won't be the case.   Hence... CNAME would be more typical.   One DNS A record per host IP address, and however many CNAMEs you want to use.

     

    Again, FWIW....

  • 3. Re: Internal dns settings
    Camelot Level 8 Level 8 (45,790 points)

    FWIW, it'll usually want to be a DNS CNAME (alias) and not an DNS A (machine) record that gets added.

    Not for the domain record, it won't.

     

    According to 'the rules', the domain record 'example.com.' may not be a CNAME record.

     

    Other records (e.g. 'www.example.com.') may CNAME to the domain ('example.com.'), but not the other way around.

    This issue is clouded by the fact that some DNS servers accept and allow it, while others don't.

     

    For reference, check section 2.4 of RFC 1912 regarding CNAME records.

  • 4. Re: Internal dns settings
    edit6969 Level 1 Level 1 (0 points)

    Thanks all for your help, got it working by adding "example.com" as a FQDN A record resolving to the website address. then in the reverse sending it to "www.example.com" I was getting confused over the FQDN status. (my 16 year old sone pointed it out to me) god I am getting old!, cheers to all

     

    Mike