I have detected an intermitted incident on my network that has been tough to pin down. From time to time, certain WinXP client machines report the a loss of connectivity to the internet. Apon a tracert to say 220.127.116.11, the tracert dies at a routed interface on 3750G 48 port switch., which is in a 4 switch stack. This routed interface is connected to a 2811 that is connected to my 100MB metro E connections from my HQ office. When the incident is occurring, other users on the same network segment are completely operational. When a client is reporting the trouble, as stated, the tracert will die at the switche's routed interface, however, a tracert to an internal destination will be successful.
Restated, i have seen tracerts fail from x.x.7.85, while at the same exact moment in time the tracert will succeed from x.x.7.30. to the same location. A ping will also fail at these moments as wll. I have verifed the the firewall is not recieving and then dropping the packets. My route in the switch to 0.0.0.0 0.0.0.0 is a staic route pointing to ip of the clustered firewall.