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  • DNS not resolving a domain

    Hello

    I have an interesting one.

    We use internal DNS servers that are configured to look-up by directly querying the root hints. DNS Forwarding is not used.

    They work fine and normally never miss a beat. However, a problem was found by one of end users. They can not resolve the name www.jetstar.com.au

    I do a NSLOOKUP on our DNS servers and it returns the address is unknown. I switch the NSLOOKUP to one of the main ISP servers in Australia and it returns an IP fine.

    I don't want to switch the servers to forwarding as this is a big company and I can't just do that, so please don't suggest it.

    I'm really baffled as to why this is happening. Can someone give some pointers to get me going so I can resolve this issue, or at least understand why it is happening.

    Cheers

    Mr Caps

  • #2
    Re: DNS not resolving a domain

    Probably Richard Branson trying to drum up business by blocking the competition!!!

    Comment


    • #3
      Re: DNS not resolving a domain

      try to examine the output of nslookup in debug mode.

      do:
      Code:
      c:>nslookup
      set d2
      www.jetstar.com.au
      you will see the DNS query flow.
      if still in trouble, paste the output here and I will try to see if I can spot anything.
      Guy Teverovsky
      "Smith & Wesson - the original point and click interface"

      Comment


      • #4
        Re: DNS not resolving a domain

        Hi

        This is the output.

        I'm guessing from what I see the COMPANY.com.au is being appended to www.jetstar.com.au.

        I'm also guessing that this is originating from the client setting appending the DNS suffix in the TCP/IP settings in the network stack. Still testing this idea.

        What do you think?

        > set d2
        > www.jetstar.com.au
        Server: DNSSERVER.COMPANY.com.au
        Address: 172.19.22.37

        ------------
        SendRequest(), len 47
        HEADER:
        opcode = QUERY, id = 2, rcode = NOERROR
        header flags: query, want recursion
        questions = 1, answers = 0, authority records = 0, additional = 0

        QUESTIONS:
        www.jetstar.com.au.COMPANY.com.au, type = A, class = IN

        ------------
        ------------
        Got answer (112 bytes):
        HEADER:
        opcode = QUERY, id = 2, rcode = NXDOMAIN
        header flags: response, auth. answer, want recursion, recursion avail.
        questions = 1, answers = 0, authority records = 1, additional = 0

        QUESTIONS:
        www.jetstar.com.au.COMPANY.com.au, type = A, class = IN
        AUTHORITY RECORDS:
        -> COMPANY.com.au
        type = SOA, class = IN, dlen = 43
        ttl = 3600 (1 hour)
        primary name server = DNSSERVER.COMPANY.com.au
        responsible mail addr = COMPANY.com
        serial = 845980
        refresh = 900 (15 mins)
        retry = 600 (10 mins)
        expire = 86400 (1 day)
        default TTL = 3600 (1 hour)

        ------------
        ------------
        SendRequest(), len 43
        HEADER:
        opcode = QUERY, id = 3, rcode = NOERROR
        header flags: query, want recursion
        questions = 1, answers = 0, authority records = 0, additional = 0

        QUESTIONS:
        www.jetstar.com.au.com.au, type = A, class = IN

        ------------
        ------------
        Got answer (118 bytes):
        HEADER:
        opcode = QUERY, id = 3, rcode = NXDOMAIN
        header flags: response, auth. answer
        questions = 1, answers = 0, authority records = 1, additional = 0

        QUESTIONS:
        www.jetstar.com.au.com.au, type = A, class = IN
        AUTHORITY RECORDS:
        -> com.au
        type = SOA, class = IN, dlen = 63
        ttl = 86400 (1 day)
        primary name server = ns1.ausregistry.net
        responsible mail addr = dns.ausregistry.net.au
        serial = 2005455722
        refresh = 14400 (4 hours)
        retry = 3600 (1 hour)
        expire = 3600000 (41 days 16 hours)
        default TTL = 86400 (1 day)

        ------------
        ------------
        SendRequest(), len 36
        HEADER:
        opcode = QUERY, id = 4, rcode = NOERROR
        header flags: query, want recursion
        questions = 1, answers = 0, authority records = 0, additional = 0

        QUESTIONS:
        www.jetstar.com.au, type = A, class = IN

        ------------
        DNS request timed out.
        timeout was 2 seconds.
        timeout (2 secs)
        SendRequest failed
        *** Request to DNSSERVER.COMPANY.com.au timed-out
        >

        Comment


        • #5
          Re: DNS not resolving a domain

          Actually scratch my last comment. It is stepping down through the suffixes. A similar search on Yahoo will do exactly the same thing and then resolve at the end.


          Originally posted by MrCaps
          Hi

          This is the output.

          I'm guessing from what I see the COMPANY.com.au is being appended to www.jetstar.com.au.

          I'm also guessing that this is originating from the client setting appending the DNS suffix in the TCP/IP settings in the network stack. Still testing this idea.

          What do you think?

          > set d2
          > www.jetstar.com.au
          Server: DNSSERVER.COMPANY.com.au
          Address: 172.19.22.37

          ------------
          SendRequest(), len 47
          HEADER:
          opcode = QUERY, id = 2, rcode = NOERROR
          header flags: query, want recursion
          questions = 1, answers = 0, authority records = 0, additional = 0

          QUESTIONS:
          www.jetstar.com.au.COMPANY.com.au, type = A, class = IN

          ------------
          ------------
          Got answer (112 bytes):
          HEADER:
          opcode = QUERY, id = 2, rcode = NXDOMAIN
          header flags: response, auth. answer, want recursion, recursion avail.
          questions = 1, answers = 0, authority records = 1, additional = 0

          QUESTIONS:
          www.jetstar.com.au.COMPANY.com.au, type = A, class = IN
          AUTHORITY RECORDS:
          -> COMPANY.com.au
          type = SOA, class = IN, dlen = 43
          ttl = 3600 (1 hour)
          primary name server = DNSSERVER.COMPANY.com.au
          responsible mail addr = COMPANY.com
          serial = 845980
          refresh = 900 (15 mins)
          retry = 600 (10 mins)
          expire = 86400 (1 day)
          default TTL = 3600 (1 hour)

          ------------
          ------------
          SendRequest(), len 43
          HEADER:
          opcode = QUERY, id = 3, rcode = NOERROR
          header flags: query, want recursion
          questions = 1, answers = 0, authority records = 0, additional = 0

          QUESTIONS:
          www.jetstar.com.au.com.au, type = A, class = IN

          ------------
          ------------
          Got answer (118 bytes):
          HEADER:
          opcode = QUERY, id = 3, rcode = NXDOMAIN
          header flags: response, auth. answer
          questions = 1, answers = 0, authority records = 1, additional = 0

          QUESTIONS:
          www.jetstar.com.au.com.au, type = A, class = IN
          AUTHORITY RECORDS:
          -> com.au
          type = SOA, class = IN, dlen = 63
          ttl = 86400 (1 day)
          primary name server = ns1.ausregistry.net
          responsible mail addr = dns.ausregistry.net.au
          serial = 2005455722
          refresh = 14400 (4 hours)
          retry = 3600 (1 hour)
          expire = 3600000 (41 days 16 hours)
          default TTL = 86400 (1 day)

          ------------
          ------------
          SendRequest(), len 36
          HEADER:
          opcode = QUERY, id = 4, rcode = NOERROR
          header flags: query, want recursion
          questions = 1, answers = 0, authority records = 0, additional = 0

          QUESTIONS:
          www.jetstar.com.au, type = A, class = IN

          ------------
          DNS request timed out.
          timeout was 2 seconds.
          timeout (2 secs)
          SendRequest failed
          *** Request to DNSSERVER.COMPANY.com.au timed-out
          >

          Comment

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