Intermittent Network Problem

[bernie321]

Hi

We have been having a small problem with 2 workstations in the building.

A few weeks ago a machine suddently could not see the network, we could not ping it from any machine nor ping any other machine.

But as far as the machine was concerned it was connected to the network: it said connected in Network Connections, the IP Address was correct, no problems in device manager, link lights were on, the link lights on the switch were on.

We tried a new network cable, using a different network port in the building , switching it off for a few minutes and rebooting it. So I rang dell and got them in to change the motherboard.

On Monday morning prior to Dell ariving i booted the machine and it connects: i can ping every machine on the network. But i put it down to an intermittent fault have them replace the motherboard and no problems with that machine.

On Wednesday another machine has the same problem with exactly the same symtoms but this machine has an event log by the NIC saying that it is disconnected - but the device manager says its fine, the machine says connected and it seems to connect every 20 or so (or so the event log says).

I believed it to either be a batch problem as the machines are identical or the Switch.

I replaced the switch for an old one that we had and the machine was fine. So Dell sent me a new switch which I fitted on Friday, today the second machine now has the same problem. I have moved the user to another workstation but I am off-site so I am waiting for the machine to hopefully come back online (as this one did before) so that I can take a look at the error log.

Any advice would be great

Thanks

 

[Freestone]

Probably not the problem, but then again...

If the network involved is using DHCP to serve up IP addressess, ensure that its pool has not been exhausted.

 

[edfair]

If not already installed, you might wnat to add NETBUI to the list of protocols.
Networking on some machines seems to go to sleep. NETBUI issues a wakeup call periodically that wakes the machine.

Ed Fair
Give the wrong symptoms, get the wrong solutions.

 

[technome]

With the involved machines I would first run Adaware and Spybot from Safe Mode, then log on to Trend Micro, if possible, and do a virus scan. Try setting the link connection to "auto" on the NIC or if it is auto, try 100 half duplex first, then 100 Full.

 

[gus669]

If your running XP make sure your NIC properties sheet under configuration --> power mangement. Has the box labeled "allow the computer to turn off this device to save power" unchecked. By default its checked. Also go into the advanced tab under configuration and make sure there are no power mgt. settings checked in there.

This is kind of a toughy. Take a known good computer (test laptop?) and plug it into the wall jack to test that connection for 20 minutes. Might as well replace the cable to rule that out. The last thing I would check is the Nic. 2 bad nics? Its happened before.

Hope this helps!

 

[bernie321]

Hi Everyone

Thanks for all your posts.

It turns out that it was a DHCP problem - RRAS was assigning conflicting IP Addresses instead of using DHCP.

Thanks again
B