I have a new client that had one existing Win SBS 2003 server (DC, AD). I went out a few months ago for the first time and corrected some DNS errors that have not recurred. Everything's been running great - until someone in their office installed a new router. The user disabled DHCP at the server and enabled it at the router. They're not actually using DHCP for workstation addresses as he created static ip addresses for the workstations at the router - and didn't specify a DNS server (internally).
The workstations have been running really slowly - and getting lots of Userenv and Autoenrollment errors.
I went out a couple of days ago to check on the Server status because they've asked me to install Exchange; this is when I first heard of the router and speed issues. I cleaned up a number of workstation permission issues and then added the File Server's IP address (192.168.0.2) to the router's DHCP section. (The workstations are using Statis IP as I mentioned, but without the specified DNS entry, they defaulted to the DNS servers of the ISP.) The workstations were then using the Server's IP address.
The users reported that everything ran much faster - and their error logs were clean.
Today, I asked them to restart the server at lunch - and the three workstations; this had not been done since I made the router DNS change. I wanted to get a fresh look at their error logs and to make sure everything was working before starting on Exchange. After that, the workstations could no longer login (Userenv and Autoenrollment again) with no access at all to the Server (permissions errors). The Server reported 7062 errors.
I saw Microsoft's pages on the Server error (218814 & 249868) and went thru and verified that DNS was ok. (The last time I looked, I was no longer getting these messages.) I verified that the workstations were getting the Server's DNS address - which they were - but they couldn't browse the internet with this address, since the Server was inaccessible. If I change the DNS address back to the router, the internet works (of course) - but still no Server.
I am no longer at the client's site. I'll be back in on Sunday. Frankly, I'm a bit stymied.
Any ideas?
If this is AD, then the workstations and the server need to use only the local DNS server. Either Root Hints or Forwarders are used for queries to the internet.
If the server goes offline, then the client won't have any DNS resolution - which is to be expected. If you add the router as the Secondary DNS entry on the NICs then they should (after a few attempts) start using the router for DNS.
The problem is that when this practice is used in a closed AD environment then network glitches or slowness causes the client to use the router (secondary) DNS for domain lookups which won't work.
Once the client has started using the router, it doesn't automatically try the Primary DNS entry again to see if it's back up until you actually reboot.
Either way, it's not a great scenario. Your best option is to have 2 DNS servers local - but even that isn't particularly cost effective or foolproof.
The only thing to do is continue to use the local DNS server only. If it goes offline and will be out of commision for a long time, then change the client DNS - other than that, just get the server back online again.
NM