Users Guide

Table Of Contents
Monitoring Switch Traffic 639
RSPAN VLAN Restrictions
MAC learning is disabled on the RSPAN VLAN. RSPAN traffic is tagged with
the RSPAN VLAN. Traffic in the RSPAN VLAN is flooded to all ports in the
RSPAN VLAN and is never sent to the CPU on the source, transit, and
destination switches. Because RSPAN VLAN traffic is flooded, it is advisable
for the administrator to consider setting the monitored ports as RX only. This
may help avoid duplicate packets when mirroring ports connected to stations
are engaged in direct connections. The administrator should also consider
using an ACL filter on a port-mirrored interface to limit uplink utilization.
The RSPAN VLAN should be configured only on the uplink/transit/downlink
interfaces. A monitored interface should never be configured as a member of
the RSPAN VLAN. The switch will not allow configuration of a monitored
source VLAN as an RSPAN VLAN.
interface Te1/0/1 Enter Interface Configuration mode for interface
Te1/0/1 (the source interface).
switchport mode trunk Configure the source as a trunk port (multiple
VLANs).
switchport trunk allowed
vlan remove vlan-id
Remove the RSPAN VLAN from the source port.
exit Exit to Global Configuration mode.
interface Te1/0/24
Enter Interface Configuration mode for interface
Te1/0/24 (the RSPAN reflector port).
switchport mode trunk Configure the uplink port as a trunk port
exit Exit to Global Configuration mode.
Command Purpose