1. New IOS
destinaiton port 0/21
Switch#config terminal
Enter configuration commands, one per line. End with CNTL/Z.
Switch(config)#monitor session 1 source interface fastEthernet 0/22
Switch(config)#monitor session 1 destination interface fastEthernet 0/21
Switch#Show monitor session 1
2. Old IOS
destinaion port 0/24
Enter configuration commands, one per line. End with CNTL/Z.
Switch(config)#interface fastEthernet 0/24
Switch(config-if)#port monitor fastEthernet 0/1
Switch(config-if)#port monitor fastEthernet 0/2
show port monitor
3. VLAN Mirroring
destinaion port 0/24
Switch#configure terminal
Enter configuration commands, one per line. End with CNTL/Z.
Switch(config)#interface fastEthernet 0/24
Switch(config-if)#port monitor vlan 1