How to cleanup DNS?
For some reason whenever I scavenge DNS, duplicate and triplicate entries for dozens of users show up, and all the sudden I have 40 computers fighting for 10 ip addresses. Is there a way to start DNS from scratch in a timely efficient manner? If I deleted all but a few static records would they rebuild themselves according to what is seen in DHCP?
dfxdeimos
You could remove all of the dynamically created records and then execute "ipconfig /registerdns" with PSExec ( http://technet.microsoft.com/en-us/sysinternals/bb897553.aspx ) against a text file with all your computer names in it.
You've got DHCP updating DNS at the moment then? If so, /registerdns really won't help.
Is what's in DHCP incorrect?
Chris
ASKER
Everything in DHCP looks accurate. Everybody's IP looks normal, and there aren't any duplicates. Only in DNS are there a massive amount of duplicate ip's for different computer names.
SOLUTION
membership
This solution is only available to members.
To access this solution, you must be a member of Experts Exchange.
ASKER
They come from DHCP with a lease, but it seems like if I restart the dhcp service for any reason and scavenge dns, all of these erroneous entries start popping up.
The duplicates can't come from DHCP Leases though, unless you have an exceptionally short Lease? Even then I assume you've set DHCP to discard the records when it's done with them?
Chris
ASKER
Yeah DHCP looks as clean as can be, which is the confusing part. It all started when I enabled scavenging in DNS to try and clear out old entries, and it started deleting ones that I was using.
ASKER CERTIFIED SOLUTION
membership
This solution is only available to members.
To access this solution, you must be a member of Experts Exchange.
Oh and I realise that doesn't really address the appearance of duplicates. I'm wondering if DHCP is pushing those in, even if they're not listed.
Does it only ever happen after you restart the DHCP service?
Chris
ASKER
Right now my no-refresh and refresh intervals are set to 1 day, is this ok? Also, this duplicate issue seems to happen after I manually scavenged stale records.
SOLUTION
membership
This solution is only available to members.
To access this solution, you must be a member of Experts Exchange.
ASKER
How do i check the DNS replication zone?
ASKER
Right now in the DHCP - DNS tab, it's set to
"enable DNS dynamic update", and with option "always dynamically update DNS A and PTR records"
"enable DNS dynamic update", and with option "always dynamically update DNS A and PTR records"
At the top of the Properties page for the zone if you open that up from the DNS Console.
Yeah, we can quickly figure out if the pollution is coming from DHCP if we disable the options you've highlighted above. It would be worth checking, if only for the sake of a quick test.
Chris
ASKER
It's set to "To all domain controllers in the AD domain" we only have 1 DC however
Ahh okay, then it'll be in AD Users and Computers, under System \ MicrosoftDNS (you'll only see them with View / Advanced Features turned on).
Chris
ASKER
I found those entries, should i do anything with them?
You see lots for systems that no longer exist? That is, you see the records that keep reappearing and really shouldn't?
Chris
ASKER
Everything on that list seems pretty accurate. There are only a few entries that shouldn't be there.
Okay, that suggests that the odd data we're seeing isn't going from AD. There will be a few odd records in there, don't worry too much about them.
If it comes down to it we can clean the zone out of AD entirely and start again with it.
Mind trying turning off the DHCP updates (the options you found above), then re-run scavenging?
Chris
ASKER
Yeah I'll turn off the updates and re-run scavenging, but I'm going to wait until Friday morning. I don't have to work tomorrow, and I don't want to plant a bomb that has half the company calling me :P
hehe I can appreciate that :) Have a good day off :)
Chris