Mac Server Losing DNS

All of our servers are statically added to AD DNS prior to building. Make sure that the ptr record is also created and verify that you can perform both forward and reverse lookups. AD Dynamic DNS causes lots of problems... usually records are not updated correctly or quickly enough or AD just doesn't do a good job of cleaning up after itself. In the past I've seen multiple A records for the same address.

We had this exact issue and our Apple system engineer helped find a solution. It turned out that we were clearing stale DDNS entries from Active Directory on a 2-3 week interval. The Windows clients update the DDNS entry on a regular basis and avoid the issue, but Macs only update the record if the local network configuration is updated or changed.

We were able to fix it by manually running this command to update the DDNS record:

/usr/bin/net -n computername -W domain.name.com -P ads register

Obviously the computer name and domain will depend on your environment. We created a launchd task to run the command every day at 3am. Since we put this in place DNS has worked as expected. One thing we've noticed is that the "net" command isn't documented very well and seems to work differently on 10.6. Hope this helps.

Ryan M Lenger
ITS - Learning Spaces Technology
2800 University Capitol Centre
University of Iowa
319.335.6374
ryan-lenger at uiowa.edu

Date: Tue, 2 Mar 2010 11:15:19 -0600

That's exactly what we have to do! Every 2-3 weeks the DDNS has to be cleared. Being a strictly Windows environment, no one is very eager to help out the Mac guys either.

You mentioned 10.6...Will this work for a 10.5.8 Server?

Yes, we are currently using the command with 10.5.8 and it works correctly. We have started to test this command with server 10.6 but the syntax or functionality has somehow changed. To sum it up, this command works great with 10.5.8, but it is unknown with 10.6.

Ryan M Lenger
ryan-lenger at uiowa.edu

Sorry, I forgot to double-check my original email for typos. The full command is:

/usr/bin/net -n computername -W domain.name.com -P ads dns register

Ryan M Lenger
ryan-lenger at uiowa.edu

Thanks. The Script works great. However, I won't know for sure until about 15 to 20 days : )...The script outputs "Successfully registered hostname via DNS", so I'm assuming we'll be fine!

I'll let you know my findings!

Thanks again!
--Noah

Is there an equivalent or relocated command for this in 10.8? /usr/bin/net doesnt seem to exist