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I have a Windows 2003 domain. DNS server and DHCP server run on domain controllers. Most workstations have DHCP enabled.

Sometimes I have weird network problems and when I diagnose them I can find two pointer (PTR) with the same IP which are linked to different hosts. Making an educated guess those hosts changed IP at the end of the DHCP lease, so one pointer is correct and corresponds to the actual IP-Host association and the other is the previous one.

This problem happens not very often. How can I configure DHCP and DNS services to avoid this behavior ?

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It sounds like you might have an old client, that is unable to update DNS dynamically. In the DHCP configuration, you can select to always update DNS A and PTR records. This option should be under the DNS properties.

There is no extra configuration required on your DNS server, the DHCP server can take over the DNS updating, and hopefully prevent your problem from reoccurring.

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Depending on the nature of your network problems, verify that a duplicate IP has not been assigned. If it has, you can expect awful network performance or a total lack of connectivity. The workstation also usually notifies and complains about this case. If duplicate IPs have been assigned, that would be the cause.

You might also have a PTR record that was not removed when it should have been, or one that was manually added. In that case, purge the erroneous one; it should not return.

In a domain, having the DHCP server update DNS is a box to tick if I recall. However, if the DHCP server and the DHCP clients are both updating DNS, it's possible (though unlikely) for you to have records like this created. Clients automatically register in the domain's DNS by default, though you can disable such behaviour in the network device's IPv4 or IPv6 properties as applicable (I think you might be able to do that via GPO as well, though I really forget).

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