Some Clients Can't Connect -- Intermittently

I have a 30-user average office network running on a Windows Server 2003 R2
server. The server is running AD, DNS, DHCP and WINS on a single box running
as the domain controller. (In the future I plan to add a second domain
controller to reduce the number of single points of failure.) This is a
single-NIC box behind a firewall device. (While the box has two NICs I have
disabled one of them.)



I am having major intermittent problems with several computers on the
network unable to connect to the server. One third to one half of the users
on the network are reporting intermittent problems connecting to the
network. Nothing is showing up in the server event logs.



Here are some clues:



1) Sometimes users can connect, sometimes they can't. Sometimes simply
shutting down and restarting two or three times may resolve the problem,
other times it won't. At least half the users report no problems connecting
to the server.



2) The server is no longer listed when browsing the network but the
workstations are. However if I Start/Run \\servername then all the server's
resources are listed and accessible. This is only so on the computers that
have no problem accessing the drives. That is, the logon.bat file works fine
for them but if I browse the network the server is not listed.



3) I have three switches on the network. The problematic workstations are
spread across all three switches so it isn't a faulty switch.



4) The only Vista user can connect to the server but the network access is
extremely slow. I tried connecting her computer to another jack with a
different cable in the event there was a cabling problem but that had no
effect. She was able to connect fine until about a week ago.



5) DNS is handed out via DHCP. The only DNS server for the clients is the
DC. The DC then forwards to the ISPs DNS servers for resolution of external
addresses.



6) Two users have reported that all their printers are missing. I have the
printers set to deploy with the domain controller group policy. Worked fine
for them and all others but stopped working for these two.



Thanks for any help. I've tried all I can think of to no avail.

Any errors if running dcdiag and netdiag?

--
Bob Lin, MS-MVP, MCSE & CNE
Networking, Internet, Routing, VPN Troubleshooting on
http://www.ChicagoTech.net
How to Setup Windows, Network, VPN & Remote Access on
http://www.HowToNetworking.com


"Bill H." <(E-Mail Removed)> wrote in message
news:YNSdnW8Tze9kGM7anZ2dnUVZ_o-(E-Mail Removed)...
>I have a 30-user average office network running on a Windows Server 2003 R2
>server. The server is running AD, DNS, DHCP and WINS on a single box
>running as the domain controller. (In the future I plan to add a second
>domain controller to reduce the number of single points of failure.) This
>is a single-NIC box behind a firewall device. (While the box has two NICs I
>have disabled one of them.)
>
>
>
> I am having major intermittent problems with several computers on the
> network unable to connect to the server. One third to one half of the
> users on the network are reporting intermittent problems connecting to the
> network. Nothing is showing up in the server event logs.
>
>
>
> Here are some clues:
>
>
>
> 1) Sometimes users can connect, sometimes they can't. Sometimes simply
> shutting down and restarting two or three times may resolve the problem,
> other times it won't. At least half the users report no problems
> connecting to the server.
>
>
>
> 2) The server is no longer listed when browsing the network but the
> workstations are. However if I Start/Run \\servername then all the
> server's resources are listed and accessible. This is only so on the
> computers that have no problem accessing the drives. That is, the
> logon.bat file works fine for them but if I browse the network the server
> is not listed.
>
>
>
> 3) I have three switches on the network. The problematic workstations are
> spread across all three switches so it isn't a faulty switch.
>
>
>
> 4) The only Vista user can connect to the server but the network access is
> extremely slow. I tried connecting her computer to another jack with a
> different cable in the event there was a cabling problem but that had no
> effect. She was able to connect fine until about a week ago.
>
>
>
> 5) DNS is handed out via DHCP. The only DNS server for the clients is the
> DC. The DC then forwards to the ISPs DNS servers for resolution of
> external addresses.
>
>
>
> 6) Two users have reported that all their printers are missing. I have the
> printers set to deploy with the domain controller group policy. Worked
> fine for them and all others but stopped working for these two.
>
>
>
> Thanks for any help. I've tried all I can think of to no avail.
>
>
>
>