Tuesday, April 3, 2012

Port Mirroring in CISCO Switch - SPAN



Catalyst Switched Port Analyzer (SPAN) Configuration

Here I'm try to give some  instructions for configuration of Port Mirroring on Cisco Catalyst Switches.
In my case I'm try to monitor,     
                              port 5 (Fe 0/5) – This is the port that I want to mirror
                              Port 3 (Fe 0/3) -  This is the Source port. I'm going to use Wireshark on this port


Now need to execute following command on the switch:

01.   Enter configuration mode:

SW1# configure terminal

02.    Create monitoring session and configure interface Fast Ethernet 0/3 as source port for that session:

SW1(config)# monitor session 1 source interface fastethernet 0/3 both

03.   Configure interface Fast Ethernet 0/5 as destination port for session 1.

SW1(config)# monitor session 1 destination interface fastethernet 0/5

04.   Then check, if everything is configured correctly:

SW1# show monitor session 1

 

Then connect a PC(with Wireshark installed) to Port 3 and monitor your PC interface card.
I have found some good CISCO site about SPAN,

And if you need some help on Wireshark use this site,