NX-OS Virtual SPAN

Virtual SPAN empowers a network administrator to SPAN more than 1 VLAN and enables the network administrator the ability to selectively chose which VLAN goes to what destination SPAN port. Example: A network administrator wants to SPAN a trunk port with VLAN 10, 20, and 30 but wants to send VLAN 10 to SPAN port ethernet 1/1, send VLAN 20 to SPAN port ethernet 1/2. and send VLAN 30 to SPAN port ethernet 1/3. Virtual SPAN enables that flexibility. This also helps reduce the number of SPAN sessions required. 

Example Nexus 7000:

Trunk Port that you want to monitor

(config)#interface ethernet 1/10

(config-if)#switchport

(config-if)#switchport mode trunk

(config-if)#switchport trunk allowed vlan 10,20,30

(config-if)#no shut

Create a SPAN Monitor Port for the Analyzer1 (must be a trunk when leveraging virtual SPAN)

(config)#interface ethernet 1/1

(config-if)#switchport

(config-if)#switchport monitor

(config-if)#switchport mode trunk

(config-if)#switchport trunk allowed vlan 10 

Create a SPAN Monitor Port for the Analyzer2 (must be a trunk when leveraging virtual SPAN)

(config)#interface ethernet 1/2

(config-if)#switchport

(config-if)#switchport monitor

(config-if)#switchport mode trunk

(config-if)#switchport trunk allowed vlan 20

Create a SPAN Monitor Port for the Analyzer3 (must be a trunk when leveraging virtual SPAN)

(config)#interface ethernet 1/3

(config-if)#switchport

(config-if)#switchport monitor

(config-if)#switchport mode trunk

(config-if)#switchport trunk allowed vlan 30

If the system is an IDS/IPS it may required the ability to learn the MAC address of the device. Include the following

(config-if)#switchport monitor ingress learning

Configure Monitor Session 

(config)#monitor session 1

(config-monitor)#source interface 1/10

(config-monitor)#destination interface ethernet 1/1,ethernet 1/2,ethernet 1/3

(config-monitor)#description SPANNING SESSION 1

(config-monitor)#no shut

You must no shut the monitor session