Workstation Loses Network Connection

[Terry Straehley]

A client has a Windows2000 network with approximately 10 WinXP
workstations. The operator at one workstation reports intermittently
losing the network connection, sometimes in the midst of an operation,
sometimes when she is logged in, but not at the console. Originally
thought it might be the NIC and replaced that, or the network cable
through the wall to the hub and tested that, but it appears to be OK.
When the connection is lost there is still a physical connection (green
light on the NIC and connected in the systray icon). The computer is
otherwise operative, but the only way to restore network connectivity is
to shut down and restart the computer.
I found that removing the network cable and connecting my laptop to it
provided network connectivity, with none when the cable was replaced in
the computer, so I thought it was a computer problem.
Replaced the computer, the replacement showed the same symptoms and even
my laptop did, when I had it sitting there transferring files for about
20 minutes.
No computer at any other drop location experiences this problem, which
appears to rule out server or hub problems.
My only possible thought at this time is that there are power spikes on
this circuit. These spikes knock the computer off the network and lock
up something in the NIC.
This doesn't affect another computer connected a few minutes after the
spike, but can't be fixed without a reboot.
I would appreciate any thoughts on this possible solution or any other
ideas that anyone might have.
Thank you for your interest.

 

[Pegasus \(MVP\)]

A client has a Windows2000 network with approximately 10 WinXP
workstations. The operator at one workstation reports intermittently
losing the network connection, sometimes in the midst of an operation,
sometimes when she is logged in, but not at the console. Originally
thought it might be the NIC and replaced that, or the network cable
through the wall to the hub and tested that, but it appears to be OK.
When the connection is lost there is still a physical connection (green
light on the NIC and connected in the systray icon). The computer is
otherwise operative, but the only way to restore network connectivity is
to shut down and restart the computer.
I found that removing the network cable and connecting my laptop to it
provided network connectivity, with none when the cable was replaced in
the computer, so I thought it was a computer problem.
Replaced the computer, the replacement showed the same symptoms and even
my laptop did, when I had it sitting there transferring files for about
20 minutes.
No computer at any other drop location experiences this problem, which
appears to rule out server or hub problems.
My only possible thought at this time is that there are power spikes on
this circuit. These spikes knock the computer off the network and lock
up something in the NIC.
This doesn't affect another computer connected a few minutes after the
spike, but can't be fixed without a reboot.
I would appreciate any thoughts on this possible solution or any other
ideas that anyone might have.
Thank you for your interest.

This may well be a licensing issue.
- Is your server a real server or is it a Windows 2000 PC pretending
to be a server?
- If it is a server, how many CALs do you have installed?
- When you lose a connection, what do you see when you issue
this command at a Command Prompt on the problem machine:
net use x: \\YourServer\SomeShare

 

[Terry Straehley]

This may well be a licensing issue.
- Is your server a real server or is it a Windows 2000 PC pretending
to be a server?
- If it is a server, how many CALs do you have installed?
- When you lose a connection, what do you see when you issue
this command at a Command Prompt on the problem machine:
net use x: \\YourServer\SomeShare

Not a licensing issue. This is a real server running Win200 Server with
15 CALs.
I haven't done that and it wouldn't work, because when it goes down, I
ping the server and there is no response.
Thanks for your interest

 

[Guest]

Terry,

I had the same problem with a Windows 2000 computer. It ended up being the
port on my Cisco Switch. You might want to move the port where the computer
is plugged in into another one. Also make sure the power management on the
network card is disabled. I have seen that to cause a computer drop off the
network. I hope one of these suggestions work.

Shawn

 

[Terry Straehley]

Terry,

I had the same problem with a Windows 2000 computer. It ended up being the
port on my Cisco Switch. You might want to move the port where the computer
is plugged in into another one. Also make sure the power management on the
network card is disabled. I have seen that to cause a computer drop off the
network. I hope one of these suggestions work.

Shawn

Shawn
Thank you for responding.
As this has ocurred to three computers plugged into the same network
drop, I doubt the latter theory.
I have sort of leaned to a variation of the first, but since we have
just a hub and it comes and goes as it does, I'm a little doubtful. We
are doing some other tests now and will probably try changing ports to
see if that helps.

 

[John Smith]

A client has a Windows2000 network with approximately 10 WinXP
workstations. The operator at one workstation reports intermittently
losing the network connection, sometimes in the midst of an operation,
sometimes when she is logged in, but not at the console. Originally
thought it might be the NIC and replaced that, or the network cable
through the wall to the hub and tested that, but it appears to be OK.
When the connection is lost there is still a physical connection
(green light on the NIC and connected in the systray icon). The
computer is otherwise operative, but the only way to restore network
connectivity is to shut down and restart the computer.
I found that removing the network cable and connecting my laptop to it
provided network connectivity, with none when the cable was replaced
in the computer, so I thought it was a computer problem.
Replaced the computer, the replacement showed the same symptoms and
even my laptop did, when I had it sitting there transferring files
for about 20 minutes.
No computer at any other drop location experiences this problem, which
appears to rule out server or hub problems.
My only possible thought at this time is that there are power spikes
on this circuit. These spikes knock the computer off the network and
lock up something in the NIC.
This doesn't affect another computer connected a few minutes after the
spike, but can't be fixed without a reboot.
I would appreciate any thoughts on this possible solution or any other
ideas that anyone might have.
Thank you for your interest.

TP cable is immune to lots of interference but not all.

Do your cables in the walls go anywhere near motors (fans in the ceiling) or
fluorescent fixtures? Bo the cables run parallel and in close proximity
(<12") to electrical wiring? Can you correlate the connection drops to
lights or motors turning on?