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    Purpose of multiple DNS per gateway

    DHCP and DNS
    dns resolver
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    • P
      pfbuddy
      last edited by pfbuddy

      Hello,

      What is the purpose of multiple DNS per gateway in General section? im using the DNS resolver in forwarding mode. I observed requests are sent to every configured item, regardless if a previous one already resolved the query. This is also true for sequential option. I just dont understand

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      • AndyRHA
        AndyRH
        last edited by

        In case one DNS server fails there is a 2nd to try. If you are using 8.8.8.8, 1.1.1.1 or your FW there is no real point.

        o||||o
        7100-1u

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        • P
          pfbuddy
          last edited by

          Thats what is expected yes but I see different behavior like described

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          • AndyRHA
            AndyRH
            last edited by

            The way MS describes it: Windows will ask the primary DNS, if a response is not seen in a short time it asks the 2nd and so on. The DNS that responds first becomes the primary.

            If you are looking a packet capture you should see some amount of time, my guess is 10's of ms, between the queries. MS never defined a "short time" when I asked about it.

            However it is said to work, it seems most OSs do what you describe, hit several before the first DNS responds. The packets are small enough I don't think the developers care and are more worried about response time.

            o||||o
            7100-1u

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