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we have an Internal DNS Server(172.16.1.1) and there is a AAA record aaa.domain.com --> 192.168.1.100

when I set ip configuration to:

Primary DNS Server: 172.16.1.1 Secondary DNS Server:8.8.8.8

then I wont be able to resolve the domain name "aaa.domain.com"

why this happens, I always though secondary DNS acts like a "backup" and will only resolve names when primary is down.

Yichaoz
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  • Is this in an AD domain? – joeqwerty Jul 08 '14 at 20:33
  • yes, it's a ADDC – Yichaoz Jul 08 '14 at 20:34
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    Then you shouldn't be configuring any external DNS servers as secondary servers. Configure all of the domain clients to only use your AD DNS servers for DNS. This includes the DC/DNS servers themselves. You can configure forwarders to 8.8.8.8 in the DNS server management console if you'd like. – joeqwerty Jul 08 '14 at 20:38

1 Answers1

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You really don't want to create a split brain dns configuration. Ideally only your first DNS server should be used, but this isn't practical in reality. If it is slow to respond the second server will be queried and may return unanticipated results.

If you really want to provide a redundant DNS server you should set up two local servers (using zone transfers or the like to keep things in sync) which then use an upstream server for any additional lookups.

Tim Brigham
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