Each TCP connection will have a timer of its own as it enters the TCP TIME_WAIT state. Once it completes the TCP TIME_WAIT period, it will be cleared from the TCP connections table. As the clearance is not a scheduled/batch process (i.e. not performed periodically), reducing this value might provide little relieve on CPU utilization.
If there are any CPU usage improvements as a result of changing this value, it might be the result of :
- keeping the connection open for a shorter period of time which would reduce the number of PCB entries which could slightly reduce the amount of time required to find a connection
- The local port will be held for a shorter period of time which would make it easier to find an open local port to bind to when initiating new connections.
SG200#configure terminal
SG200#(config)tcp-ip tcp-2msl ?
<seconds>
SG200#(config)tcp-ip tcp-2msl 120
ok
SG200#(config)exit
SG200#show tcp-ip
.....
TCP 2MSL timeout: 120 seconds <<<<< Default value
.....