PTR Records on Internal DNS

ipconfig /flushdns only clears the local DNS cache

Your PTR's should be created automaticaly when a computer registers with DNS.  I don't know how to automaticaly remove PTR records, but you can safley delete the ones for your internal domain.  You may have to recreate the ones you need.

You may also need to check your DHCP settings
Right click on your DHCP server and go to properties
On the DNS tab make sure the following are checked;
Enable DNS dynamic updats according to the settings below

Dynamically update DNS and PTR records only if requested by the DHCP client

Discard A and PTR records when lease is deleted

eb

actually, you probably do not need a reverse lookup zone, in my company, we have about 100,000 workstations, and do not use a reverse lookup zone.

i would remove it and your problem is solved.

Good Luck,

ok, I found a source of what I believe is part of the problem.  I recently upgraded a domain controller to 2k3, and it installed DNS on this server, as well (I don't remember doing, but maybe I did without thinking).   I have removed DNS from this server and I am cleaning up the reverse zone on the other server.  Removing the reverse zone isn't an option.  We are a software dev shop, and need both forward and reverse capabilities.

ebjers, i checked those settings before posting and they are all checked, but for some reason old pointers aren't getting cleaned up when ip's are reassigned.  Possible because I had 2 internals and the dhcp server only knew about one of them.  I think the second dns was replicating old records to the primary internal after they were cleaned.

I will keep you posted.  If this resolves it, I will assign points accordingly.  Thanks for the replies.

Hi guys,

Sorry to barge in, but I was going through a few of the older questions and I wanted to drop a quick comment in about this one.

Is DHCP pushing records into DNS for you - you will have to have configured this if it is, it doesn't do it by default? If so then it should be cleaning up after itself as it turns off the clients ability to register their own records.

If not, you need to configure the Aging options on the Reverse Lookup Zone (and any other dynamically updatable zone) and ensure at least one of your DNS servers is performing Scavenging to keep it clear of old records. If you don't know how to configure that then:

Aging: Set on each zone under Properties, General, Aging
Scavenging: Set on each DNS Server under Properties, Advanced, Scavenging (one box for Enable and one for the Period - 1 day is generally more than enough).

In an ideal world the aging options; No-Refresh Interval and the Refresh Interval added together should match your DHCP lease time.

HTH

Chris

Thanks for chiming in Chris, scavenging is set for both forward and reverse zones for 1 day.  I still seem to be getting a few dupes, as if DHCP isn't cleaning records as it reassings addresses. (didn't notice before, but I have dupes in both forward and reverse zones)

I also noticed in Properties->Name Servers for forward and reverse zones, I still had the unintentional DNS server listed as a name server.  I removed it and will continue to monitor.

You should only have internal servers listed as name servers, so removing it was the right thing to do.

How do you have the Aging period configured on the zone?

Chris

I forget how to reference a question to be closed by support.  The question hasn't been answered.

My apologies, I assumed they were the same thing.  I set aging limits as you suggested and I don't see any dupes.  Thanks for the help

No problem, glad it's all working now :)

Chris