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My 2008 R2 Domain Controller has no PTR record for itself

Hello experts,

Just came across an odd situation where one of my Windows 2008 R2 domain controllers does not have a PTR record in the Reverse Lookup Zone of my Active Directory integrated DNS.  

I noticed this by doing an nslookup from my workstation.  Since my primary DNS is the server I'm referring to above, the nslookup window starts with "Default Server: UNKOWN" and the IP address of the server below it.  

All DNS resolution and network functionality is fine.  I'm not sure if this existed for a while or whether it has to do with the fact that I just did some Windows Updates on just this one DC and rebooted it.  

Will the PTR record come back on its own?  Will I cause any problems by simply doing a "ipconfig /registerdns" command on the box.  The TCP/IP properties on the DNS tab have the "register this connection in DNS" option selected.

Please provide feedback - thanks!  I'd like to correct this the right way (and understand what happened here).
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dpmoney
Asked:
dpmoney
1 Solution
 
Andrew DavisManagerCommented:
doing  an Ipconfig /registerdns will cause no issue. It is perfectly safe.

Let us know how you go.

Cheers
Andrew
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Leon FesterCommented:
"Default Server: UNKOWN" and the IP address of the server below it.  
You typically see this if there is no reverse lookup zone for the subnet your server resides.

DNS registration of DC records should occur under any of the following conditions:
You restart the server(reboot)
You restart the netlogon service
These two options will impact on your server;
reboot - server unavailable.
restart netlogon - no user authentication from that server until the service restarts.

The following commans should not impact your server or clients.
You run ipconfig /registerdns
You run dnscmd /dsregdns

You can also add the record manually if desired.
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dpmoneyAuthor Commented:
This worked in our simulated lab environment without issue so we plan on putting in production as well.  Thanks for your assistance.
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