I have a machine on my network that has, for no good reason, just stopped accepting any inbound traffic. It has no problems accessing the network and files shares or going out onto the web but no one has access to it at all. Pings fail and accessing file shares fail with "The network path was not found".

It's acting as if there is a firewall of some sort running and it's actively dropping pretty much all inbound traffic. But as far as I can tell, it only has Norton Anti-Virus installed and the Windows firewall active. I've went and disabled both, make sure port filtering is disabled under TCP/IP and I still have do not have access to the machine.

If I boot into safe mode with networking, then there is no problems. It must be some application or service that is running but I can't figure out what. I've run HijackThis and nothing in that list looks out of the ordinary.

The machine is running WinXp sp3 and kept up to date with the latest maintenance.

Anybody has any ideas? Thanks

  • Any restore points?, I actually find that works pretty well, to my surprise :-) – Kyle Brandt Nov 11 '09 at 18:15

Anything in events log?

  • there was nothing in the event log when this all started but i'm glad you mentioned it again. i checked the event log after rebooting normally with all the various services turned on. i noticed some errors regarding a truevector service being unable to start. digging around reveals that it belongs to zonealarm, which shares some of its functionality with a cisco vpn client we are using. for some reason, the stateful firewall built into the vpn client got turned on and was blocking everything. doesnt look like the firewall is configurable in any sort of way. /sigh. – tabo Nov 11 '09 at 16:46
  • any chance of digging through the registry for a on/off switch? – Skaughty Nov 11 '09 at 17:02
  • If windows firewall is active, check that there is an exception set for Truevector service – alexm Nov 11 '09 at 17:39
  • there's an option to turn on/off the firewall in the settings. just had to find it. other than that tho, there are no configurable options for it that i can find. – tabo Nov 11 '09 at 17:47
  • 1
    Here - forums.techguy.org/windows-xp/… - people are saying that problem is solved by installing updated cisco vpn client or re-installing same version. – alexm Nov 11 '09 at 18:02

I get this intermittently with an XP machine when downloading torrents. I think it's just that uTorrent hits the IP stack so hard that it can't do anything else; I suspect that anything else that opened scores of connections simultaneously would create the same problems on XP.

I suspect you're right that it's TrueVector, but hope this will be useful for the next person with the same problem.

  • If the IP Stack was troubled, a reboot (without safe mode too) would reset it. Only a firewall rule 'may' continue to stick. I therefore suspect an incoming connection load to a Windows machine cannot cause this problem. – nik Nov 11 '09 at 17:57
  • If the IP Stack is troubled because a P2P application is opening huge numbers of connections, and the P2P app restarts after rebooting, then it would appear to be persistent across a reboot. netstat -an is often a good idea. – Richard Gadsden Nov 13 '09 at 11:21

Try stopping the windows firewall service. On one machine I had the Windows Firewall block everything despite being turned off in the options.


Double Check your RPC services in your services& applications they might have stopped for some reason.

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