We are using a Catalyst 2950T to capture the traffic of our network. We set up monitor session from a source port to a destination port, where a laptop runs tcpdump. What we observed was that the tcpdump started seeing only broadcast traffic after a couple of days. Then we had to restart the switch in order to see normal (ingress/egress) traffic again. We tried to disable/enable the session, but no avail. We also tried a same set up on a Cat4006 switch (CatOS), same issue.
Does anyone know that Catalyst switch may have some limited resources for the SPAN session, and after certain number of packets, it just stops working? Is there any way to fix/workaround this issue besides restarting the switch?