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How client query works with DNS forwarder RRS feed

  • Question

  • Hi this is regarding the DNS query;

    We have Windows 2012 server DNS Setup and ISPs DNS are set in the list – added forwarder, there are about 5 different ISPs DNS IPs address, so in this I wish to know how DNS query works, Does it checks for all DNS ips at once or it goes querying one by one for all 5. Suppose if query is not resolved by 1 IP then it check for 2 IP and this case if query is not resolved by very first server in the list then there will that much time delay if query is successfully addressed by 4th IP.

    we are experiencing Latency issue with Vonage Voice calls so - just want to find out Vonage Calls relation with.

    -Atul A


    TheAtulA

    Thursday, November 15, 2018 12:35 PM

Answers

  • Hi,

    When forwarders are configured on a DNS server, when it receives a DNS query for a name for which it is not authoritative, meaning a query outside the scope of its control, one it has no knowledge of, the server will forward the request to whatever forwarder(s) were configured on it.

    From a network and performance efficiency perspective, having a single forwarder is generally more efficient than using multiple forwarders. This is because of the way DNS queries work. Whenever a DNS server receives a query and resolves it using forwarders (as with Root Hints), it caches the results it sent back to the client. Since query results are concentrated in one forwarder’s cache, any subsequent queries to the same names will be resolved locally from that DNS’s cache. This decreases the Internet traffic over the network and improves the response time for DNS clients.

    Best regards,

    Travis


    Please remember to mark the replies as an answers if they help.
    If you have feedback for TechNet Subscriber Support, contact tnmff@microsoft.com

    Friday, November 16, 2018 5:40 AM
    Moderator

All replies

  • Hi,

    When forwarders are configured on a DNS server, when it receives a DNS query for a name for which it is not authoritative, meaning a query outside the scope of its control, one it has no knowledge of, the server will forward the request to whatever forwarder(s) were configured on it.

    From a network and performance efficiency perspective, having a single forwarder is generally more efficient than using multiple forwarders. This is because of the way DNS queries work. Whenever a DNS server receives a query and resolves it using forwarders (as with Root Hints), it caches the results it sent back to the client. Since query results are concentrated in one forwarder’s cache, any subsequent queries to the same names will be resolved locally from that DNS’s cache. This decreases the Internet traffic over the network and improves the response time for DNS clients.

    Best regards,

    Travis


    Please remember to mark the replies as an answers if they help.
    If you have feedback for TechNet Subscriber Support, contact tnmff@microsoft.com

    Friday, November 16, 2018 5:40 AM
    Moderator
  • Hi,

    Just checking in to see if the information provided was helpful.

    Please let us know if you would like further assistance.

    Best Regards,

    Travis


    Please remember to mark the replies as an answers if they help.
    If you have feedback for TechNet Subscriber Support, contact tnmff@microsoft.com

    Wednesday, November 21, 2018 9:06 AM
    Moderator