Connection in Closing State. CSM

lfrc8554 · ‎10-17-2007

Hi, I have a couple of Cat65k with one CSM on each running in active-standby mode. The active CSM shows thousands of connections in CLOSING state while the passive CSM shows the same thousand connections in ESTAB state. When we look at the connections in the real servers they do not see connections that would match the ones that the CSM repporst as CLOSING. The connections can stay in CLOSING mode for several minutes. I am running version 4.2.5. Any ideas of why all these CLOSING connections? What troubleshooting steps do you suggest?

Thanks.

Syed Iftekhar Ahmed · ‎10-17-2007

Sessions stuck in CLOSING state indicates that

final FIN ACK from either client/server has not been seen.

You should sniff the CSM port channel and look for packets that match any of the flows which is in closing state on the CSM.

You can also set the idle timer under the vservers to some lower value and see if the CSM connections remains in the "CLOSING" state for defined time.

Syed

lfrc8554 · ‎10-18-2007

The idle time-out is at default (3600) and your idea is a good one. In terms of typical values, we have approximately 300 connections pers sec. Do you see that having on average 1000 connections in 'closing' mode at nay given time is somewhat normal?

Luis