DNS upper and lower case records

Question

_{Wednesday, May 4, 2011 9:18 PM}

Hi,

Looking at our DNS (AD integrated) we see records in both upper and lower case. As far as we can see, there does not appear to be a logical explanation for this, I have checked the NetBIOS names of the machines involved and even for some of the upper case entries the machine names are in lower case. Can anoybody explain what determines this and how we can get it so all (dynamic) DNS entries are lower case? Although DNS itself is obviously case insensitive, some other apps like SCVMM and DPM pick up the machine names from DNS and server lists in those programs look messy with mixed case. 

Thanks

Meint

All replies (3)

_{Thursday, May 5, 2011 8:45 AM ✅Answered | 1 vote}

Hi PasstheDutchie,

If you have AD-integrated zone , then convert it to Primary zone. Then right-click and click "Update Server Data File". The zone will be written to a file in your system32\dns folder. Make a backup copy of the file, then open the original file in notepad. Make the changes you want to make , be careful. Then increment the "serial number"
then Save the file and restart DNS.

Convert the zone back to AD-integrated aganin then restart the dns services.

Good Luck :)

Abeer Omar, MCP,MCSA,MCSE,MCTS.MCITP

_{Thursday, May 5, 2011 2:37 PM | 1 vote}

DNS is NOT case sensitive, however it is case aware. If a registering machine's hostname is in upper case, when it registers, it will honor the case and will enter the record into DNS as such.

If the machine's host name is upper case and is a DHCP client, and you have DHCP set to register for the client (configured to use credentials), or if you don't it will honor the case as well.

If you look at the zone data as AbeerOmar suggested, to change it, during the next registration cycle (DCs every 24 hours, clients/members every 7 days) it will change back to whatever the registering machine is.

So it would be helpful if you can describe if these are DHCP clients, static clients, if using a Windows DHCP and if so, if DHCP credentials have been configured, using WINS, GlobalNamedZones, etc, to better point you in the right direction.

But as I mentioned, the basic thing to look at is that DNS is not case sensitive, but it case aware and will honor the case of the registering host.

Ace

Ace Fekay
MVP, MCT, MCITP EA, MCTS Windows 2008 & Exchange 2007 & Exchange 2010, Exchange 2010 Enterprise Administrator, MCSE & MCSA 2003/2000, MCSA Messaging 2003
Microsoft Certified Trainer
Microsoft MVP - Directory Services

This posting is provided AS-IS with no warranties or guarantees and confers no rights.

_{Tuesday, May 10, 2011 3:55 PM}

Thanks for both your suggestions and apologies for the delay in replying, for some reason I didn't get a notification an update was posted. The machines are static IP's (servers) and as far as I can see the machine names were all done in lower case from the moment they were built. Yet I have certain entries in the DNS in upper case and others in lower case, same thing in the lab. I will try the DNS suggestion in the lab to see if the server names all stay in the same (lower) case or if they get amended back to lower case.

Thanks for your input and suggestions.

Meint