AD / DNS problem

[Number6]

Sorry for the vague thread title but this is a very strange problem.

 

SBS 2003 network.

 

Everything is fine except that I suddenly can't remote into some of the clients, some I can but some I can't. This occurs whether I use TS from the server or Dameware Mini NT from my workstation.

 

There's no other obvious problem on any of the affected client machines, they can log on, see the network, browse the net, connect to Exchange, etc.

 

I can see all the clients using net view, can ping them by name or IP, etc.

 

If I go to CP > System > Remote on any of the affected machines then it appears that Remote Access is configured; if I attempt to add RA users I can find the AD, I can find the user in the directory but when I OK the dialogue box I get an error along the lines of "the user or object cannot be added because the domain cannot be contacted or does not exist".

 

Windows Firewall is correctly configured to allow Remote Desktop.

 

As I said, not all client machines are affected and some I can remote into perfectly OK.

 

A bit stumped at the moment, does anyone have any ideas?

Edited June 24, 2009 by Number6

[leco]

Do the computers in question wake on lan? I had some that when they were in stand-by (as in disc drive stopped, monitor off etc) I couldn't remote in. Now I'm desperatly trying to remember what I did to aleviate that:(

[Number6]

Do the computers in question wake on lan? I had some that when they were in stand-by (as in disc drive stopped, monitor off etc) I couldn't remote in. Now I'm desperatly trying to remember what I did to aleviate that:(

 

We don't allow PCs to go into standby, all power saving settings are turned off.

[Number6]

If I use nslookup -d mydomain the last line says 'cannot find mydomain'

 

If I use nslookup -d mydomain.local then all appears OK

[ricki]

HI

 

Can I ask some questions.

 

Can you check to ip on a machine with a problem that cannot be seen and check its ip.

 

Now flush your dns on the machine that cannot see it with ipconfig /flushdns

 

Can you ping the machine by name and does it have the same ip as the actual machine. on the ping.

 

Check on the machine that has the problem if group policy has not applied to the client.

 

Do you have several dns servers.

 

Do you have several domain controllers.

 

If the policy is not applying check that replication is happening on the domain controllers.

 

If the ip is different on the client and the look up machine check that replication is happening on you dns servers.

 

Netdiag and dcdiag might give you a clue.

 

If they find something have you tried rebooting the server or the services.

 

Also are the problem pcs plugged into the same switch. Is a switch playing up and have you tried turning the switches off for about 10 mins and then turning them back on.

 

Just some ideas.

 

Richard