Please see this link,

http://www.cisco.com/en/US/docs/switches/lan/catalyst4500/12.2/31sg/configuration/guide/span.html

Step 1.

Switch(config)# vlan 901

Switch(config-vlan)# remote span

Switch(config-vlan)# end

Step 2. Assuming gigabitethernet0/1 is the port that you want to sniff

Switch(config)# monitor session 1 source interface gigabitethernet0/1 both

Switch(config)# monitor session 1 destination remote vlan 901

Switch(config)# end

To get the information that is flowing to the remote VLAN (on our case 901), this needs to be done on the switch where you have the device that will receive the RSPAN traffic.

Step 3.

Switch(config)# vlan 901

Switch(config-vlan)# remote span

Switch(config-vlan)# end

Step 4. Assuming gig0/5 is the port where you have the PC/server with the shiff capture software.

Switch(config)# monitor session 1 source remote vlan 901

Switch(config)# monitor session 1 destination interface gig0/5

Switch(config)# end

All the switches on the path between initial switch and ending switch should have the remote VLAN, follow step 3 , also VTP pruning should be disable in order to allow the VLAN to be enabled and present on all the switches.

Regards,

~JG

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