TCPIP mysteriously stops working

[Guest]

I am having a problem which seems to happen whenever I run certain software
packages, which are all load-testing packages for automating the testing of
websites (opensta, neoload, watir, and others).

The problem is that at some point my TCPIP stack stops working. The symptom
is that while I can ping ip addresses and get responses, other operations
don't work. For example name resolution stops working, though I can ping my
name server. Running a network monitor on the same box (ethereal), I don't
see any DNS traffic going in and out (my network is switched, so I only see
my own traffic even when the ethernet is in promiscuous mode). I tried ssh to
other boxes by IP address using Putty, and that just hangs, and the command
line ftp also hangs even when using IP address.

Its as though I had a firewall blocking all protocols but ping, but I have
windows firewalling turned off.

Once this happens I have no way to resolve it but to reboot.

Can anyone help me resolve this?

The same software works fine on other machines. I know I can reinstall
Windows, but that is quite an undertaking and if I don't know the cause I may
just re-create the problem.

Thanks

 

[P.J. Whoopie]

From a command window, try typing "netstat -a -n" and find out how many
sockets you have and what state they are in. It sounds like you have used
up all of your ports, and may have sockets in WAIT states closing down.

I've also seen this problem when a process leaked handles, so you might also
launch task manager, click View->Select Columns... then check Handle Count
and click OK. Sort by handles and look for a process that is using tens of
thousands of handles. That would be a bad leak.

YMMV

P.J.