Windows 2008 doing AAAA record lookups as well as A lookups even when it has no IPv6 enabled?

Discussion in 'Windows Server' started by Peter Lawton, Mar 2, 2008.

  1. Peter Lawton

    Peter Lawton Guest

    When doing a DNS lookup from a Windows 2008 box it does a normal A record
    lookup first then it does an AAAA record lookup, even when IPv6 isn't
    enabled, doubling the name lookups the machine does for no good purpose and
    doubling the load on the DNS servers.

    The only reference I can find on the MS site is for Vista, but implies that
    this shouldn't be happening :-

    "The DNS Client service in Windows Vista has been designed to minimize the
    impact on DNS servers when performing DNS name queries through the following
    If the host has only link-local or Teredo IPv6 addresses assigned, the DNS
    Client service sends a single query for A records.
    If the host has at least one IPv6 address assigned that is not a link-local
    or Treed address, the DNS Client service sends a DNS query for A records and
    then a separate DNS query to the same DNS server for AAAA records. If an A
    record query times out or has an error (other than name not found), the
    corresponding AAAA record query is not sent."

    I've unbound IPv6 from all adapters and added the registry entry
    Components" value off to disable IPv6 completely.

    The same behavior seems to happen on both Windows 2008 server and Vista with

    Does anyone know how to stop these unnecessary AAAA lookups?


    Peter Lawton
    Peter Lawton, Mar 2, 2008
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