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DNS server is not routing traffic

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  • DNS server is not routing traffic

    Hello all,

    I'm having issue with my integrated AD DNS server. the server having issue routing traffic externally. It's sometime slow and sometime traffic is not even routing.

    The clients are having issue to browse externally, even when I do NSLookup on the server for it gave me the server unknown error

    can someone give me a direction on how to trouble shooting this?

    Last edited by Humannetwork; 31st August 2012, 14:51.

  • #2
    Re: DNS server is not routing traffic

    Your DNS server configuration is incomplete. It may be accurate for any address lookups inside your domain, but you have to have 'forwarders' configured, as well as 'root hints' for proper Internet resolution.

    Your ISP should have provided IP addresses for their DNS servers, which would act as forwarders for you. Read the MS article at: to find out how to set this up.
    MSCA (2003/XP), Security+, CCNA

    ** Remember: credit where credit is due, and reputation points as appropriate **


    • #3
      Re: DNS server is not routing traffic

      First of all your DNS server does not route traffic.

      Have you tried the tests on the DNS server console??

      Have you got forwarders setup??

      Have you opened UDP port 53 on your firewall to allow your DNS server access to external DNS servers??


      • #4
        Re: DNS server is not routing traffic

        You say sometimes it works and sometimes it is slow. Which could imply you do have forwarders but they don't always work.
        If you can't speak to your ISP (assuming their forwarders are the ones you are using) then I would suggest using another provider to test with opendns or similar.
        Can you still ping your ISPs DNS servers (assuming icmp is allowed) when you can't resolve DNS?
        Do you have any other internet related issues at the same time?

        Please read this before you post:

        Quis custodiet ipsos custodes?