Dynamic DNS updates not being created but DHCP working

[_techie_]

I have built a new VLAN for our PC suites. Everything is fine apart from certain PCs not updating DNS records dynamically when booting. They do however get a DHCP lease and operate without error as an end user would experience during logon and normal use.

I have tried the following with no success!:

 

Different CAT5 cables and in different switch ports on the same switch

 

Updated switch firmware to latest from HP in suite.

 

Updated NIC drivers on machine.

 

A brand new Win7 WIM built from the ground up (install.WIM added to WDS, and captured back after sysprep/generalise etc etc), deployed to same model with latest drivers.

 

If I manually register DNS on each PC that fails, it's fine, but I really want to fix this issue. Aside from updating core switch firmware, I really at am a loss as to why this isn't working. No errors in eventvwr on PC for System or DNS on PC or DNS server.

 

We do have allow dynamic updates from non AD sources turned on at server level. This was done before I started due to the high level of Apple devices now on the LAN/WLAN.

 

Most PCs on new VLAN are operating okay. We just get the odd ones that don't work. I can only think dodgy NIC in the PC otherwise.

 

Any suggestions?

[jbutlin]

It sure sounds like you've tried almost everything! So if you manually assign IP addresses and DNS, it works OK? Are these PCs the same make and models as the others, or are they different?

[jbutlin]

I don't know if there is anything helpful in this link: Some computers not updating new IP in DNS - TechRepublic

[_techie_]

@jbutlin

 

Hi. Not not assigning the PC's IP manually. They are getting them from DHCP correctly, just not registering back to DNS.

They are different models (DELL Optiplex 790's and HP DC5700's, but same model in different rooms).

I have tried removing an account from AD and re-adding to the domain.

I think a rebuild of the suites during the Summer with fresh LAN cables might do the trick. Keep things simple and slowly build up...

Thanks for the suggestions however. :-)

[MatthewL]

Have you disabled IPv6 on the machines in question? I know some of the Dell & HP desktops with this enabled have caused random issues in the past.

[_techie_]

No I haven't... Can you do this via GPO?

[jbutlin]

I think you can, but it's not that simple - it involves registry keys

[MatthewL]

Not sure, could be worth just trying it on a few machines first manually and see if it has any results and then script it.

[Pashers]

Have you tried putting a non-working machine onto the same port as a working machine? If the machine then works, it might be the couple ports on the switch not configured?

[chazzy2501]

you can set a DHCP option (on the dhcp server) for it to update the DNS rather than the client. (it's more secure as well)

[_techie_]

Yes ours is setup that way.... That's why I'm troubleshooting the issue!

[Pashers]

Just out of curiousity have you tried deleting the PC names from the DHCP and DNS entries? Then let them be recreated?

Also there isn't a duplicate Mac address hanging around is there?

[_techie_]

Yes, deleting the DHCP entry also deletes the DNS. Rebooting the client solves the issue, but it returns anyway.

I think we have got to the bottom of the issue... Think it's a dodgy image that was being rolled out, onto machines that had been rebuilt. They probably didn't generalise the image during sysprep I can only assume before capture.

Rebuilding the OS, seems to solve the issue.

[Pashers]

I had an instance when about 6 machines had the same (on board) Mac address. That caused me a headache with imaging and other things.

Odd, that it was the image.