Administrator Guide

570 Monitoring Switch Traffic
RSPAN Transit Switch
The following is an example of an RSPAN transit switch configuration. The
RSPAN VLAN should be configured as a remote-span in order to disable
MAC learning on the VLAN. In this case, the transit switch ports are
configured as trunk ports (members of all VLANs) and may be used by other
traffic. Packets on the transit switch (in this example) are received and
transmitted tagged.
1
Configure remote span on a VLAN:
console#configure
console(config)#vlan 723
console(config-vlan723)#remote-span
console(config-vlan723)#exit
2
Configure the transit switch ports in trunk mode:
console(config)#interface te1/0/1
console(config-if-Te1/0/1)#switchport mode trunk
console(config-if-Te1/0/1)#interface te1/0/2
console(config-if-Te1/0/2)#switchport mode trunk
RSPAN Destination Switch
The following example shows the configuration of the RSPAN destination
switch. The RSPAN mirrored packets are transmitted over the destination
port untagged.
1
Configure remote span on VLAN 723:
console#configure
console(config)#vlan 723
console(config-vlan723)#remote-span
console(config-vlan723)#exit
2
Configure interface te1/0/1 as the destination port.
console(config)#interface te1/0/1
console(config-if-Te1/0/1)#switchport mode trunk
console(config-if-Te1/0/1)#switchport trunk allowed vlan 723
console(config-if-Te1/0/1)#exit
3
Configure a mirroring session with the remote VLAN 723 as the source
and interface gi1/0/1 as the destination port:
console(config)#monitor session 1 source remote vlan 723
console(config)#monitor session 1 destination interface
gi1/0/1