Cisco Switched Port Analyzer (SPAN)

The Switched Port Analyzer (SPAN) , which is also called port mirroring, sends the network traffic to a network analyzer(sniffer).

In this example there is a sniffer on port Gigabitethernet5/1.We want to capture all network on port GigabitEthernet5/2 and send the copy of this traffic to port GigabitEthernet5/1:

 

monitor session 1 source interface GigabitEthernet5/2

monitor session 1 destination interface GigabitEthernet5/1

In this example there is a sniffer on port Gigabitethernet3/1.We want to capture all network on vlan 100 and send the copy of this traffic to port GigabitEthernet3/1:

monitor session 1 source vlan 100

monitor session 1 destination interface GigabitEthernet3/1