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DNS Failover

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DNS Failover

paul.kuczwara
Good Morning All,

I have a question about DNS failover?

I have and internal domain, which has 'Forward Lookup Zones' to both the internal and DMZ zones. When the internal PDC goes down, I would expect that the secondary internal DC / DNS server would pick up the slack. What I am finding is that when I take the PDC off-line the other DC/DNS server is not picking up the slack. I have a TTL of 1 hour on both DC?s. With a Refresh Interval of 15 minutes, Retry Interval of 10 minutes, and expires after 12 hours. Is there some other issue / configuration setting that I am missing? Any advice will be greatly appreciated.

Regards,
Paul
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    christianshiflet

    What are your DNS settings in DHCP and what are the DNS settings on your clients? Have you set the DNS for your scope to point first to your internal server and then to a backup or external source? This can be done by opening the scope in the DHCP console, right-click on "Scope Options" and select the "Configure Options" option. From there you should be able to set the DNS options for your DHCP scope, where your clients will reterieve their DNS settings. The lookup zones affect how your internal DNS server finds hosts but if it is down, your clients cannot make requests of it.

    Let me know if that helps or you have further questions. Thanks.

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    paul.kuczwara

    Good Afternoon Christian,

    Thank you, your suggestion got me headed in the correct direction. I found two issues that were causing me problems. First, I did not have the failover DNS server listed in DHCP DNS "array of DNS servers". Secondly, I had mistyped the secondary IP address. Once those issues where solved All tested OK.

    Regards,
    Paul

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    christianshiflet

    Glad to help and glad you got it solved! Let us know if you have any other questions.

  • +
    0 Votes
    christianshiflet

    What are your DNS settings in DHCP and what are the DNS settings on your clients? Have you set the DNS for your scope to point first to your internal server and then to a backup or external source? This can be done by opening the scope in the DHCP console, right-click on "Scope Options" and select the "Configure Options" option. From there you should be able to set the DNS options for your DHCP scope, where your clients will reterieve their DNS settings. The lookup zones affect how your internal DNS server finds hosts but if it is down, your clients cannot make requests of it.

    Let me know if that helps or you have further questions. Thanks.

    +
    0 Votes
    paul.kuczwara

    Good Afternoon Christian,

    Thank you, your suggestion got me headed in the correct direction. I found two issues that were causing me problems. First, I did not have the failover DNS server listed in DHCP DNS "array of DNS servers". Secondly, I had mistyped the secondary IP address. Once those issues where solved All tested OK.

    Regards,
    Paul

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    0 Votes
    christianshiflet

    Glad to help and glad you got it solved! Let us know if you have any other questions.