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cisdoz2

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XP loss of connectivity on 2003 network

We've recently developed an issue on our network.  The network spans several campuses and are connected via fiber using Catalysts switches with routing enabled as the campuses are on different networks.

The problem:
Several XP workstations start up and can't connect to the internet.  Telnet does not work either.  Howerver, I can ping, traceroute, nslookup, all with success.  Mapped drives do not work either.  Most of the time, a reboot takes care of the problem and everything works as is should.

Quite a few of the machines it happens on are repeat offenders.

I have not seen any issues with most of the machines and none with any of the servers.  It seems to be random and scattered across all campuses.

I have checked various logs and event viewers and don't really see anything incriminating.

Anyone have any suggestions as to what I should be looking for or how to proceed?
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aiaila

Here are few things to check:

1. Do you have any Antivirus running on these machines? If you do check the settings.
I had similar problem and Antivirus was blocking the connection to the network. I could do ping, traceroute and nslookup with success but it would just lose the internet and network connection.

2. check is the internet explorer settings. It might be setup for dialup and that why you are not getting connected.
3. check DHCP lease duration. What is the DHCP lease duration?

Good luck and post back if you find the reason..

when you 'cant connect to the internet' and cant 'telnet', what happens when you type ipconfig?

Do you have an IP address yet?
One thing that I have noticed when workstation lose their connection intermitently is check the network connections.

On the client machine-
go to  network connections- Advanced- Advanced Settings-
Under connections - make sure that the Local Area Connection is in the first position.  

Sometimes a VPN client or other adapters get placed in the first position causing the workstation to look other places than the LAN.  

Something else quick to try.  


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Craig_200X

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ALSO sometimes the computer shuts the network card driver off.. check device manager / network card properties ... make sure the powermanagement option ALLOW THE COMPUTER TO TURN OFF THIS DEVICE is NOT checked.

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ASKER

Thanks for the quick responses.  We do have the same Anti-virus running on all of our machines.  I will check for the Anti-virus block.  We do not use DHCP.  All of our machines are static and when I do a ipconfig on the machines, all the info shows correct.  I have checked the network properties, including the Advanced settings and they were correct.  Though some of the affected machines are connected to hubs, others plug directly into 3Com and Cisco switches.  I have not checked the power management properties so I will check that as well.

The network icon shows to be connected and as I mentioned, I can do ping, traceroute and nslookup.  I thought it may be a network loop somewhere but I haven't found one.  I have been looking for duplicate mac addresses on different switchports and have found none.  In one lab, only one machine was affected while all the others worked perfectly.  The machines are identical and were imaged with Ghost.  I even rechecked all computer names and addresses and then reset the SID on all the lab computers and ran the Network ID wizard again.  All worked great and this morning, the same machine failed.  A reboot took care of it.

I will check these items and post my results.
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ASKER

Thanks again for the suggestions.  I stayed last night and rebooted all of our backbone switches (some had been up for 26 weeks) and this morning all went well.  I will watch a couple of days and see how things run.
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ASKER

Ok folks, there must have been something weird in one of the switches.  In the days following the reboots, I have seen no issues such that I spoke of earlier.  We have quite a few switches, so I usually don't go around rebooting them all but I have never seen anything like this.  Anyway, thanks again for your input.  If there are not objections, I will have this question closed.
FYI: I did suggest rebooting hubs (switches)...

"are the offending machines plugged to a cheap hub? sometimes a power drop/reset can cause a dying/frozen network card/port to come back to life.. (like a heart stopping/fibulator shock.)"