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Catalyst 2950 Desktop Switch Software Configuration Guide
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Chapter 21 Configuring SPAN and RSPAN
Configuring RSPAN

Configuring RSPAN

This secti on descri bes how to configure RSPAN on your switc h. It cont ains this co nfiguration
information:
•RSPAN Configur ation G uide line s, pa ge 21 -1 4
•Creatin g an RSPAN Session, pa ge 21-15
•Creating an RSPAN De stination Session , page 21 -16
•Removing Ports from an RSPAN Session, page 21-17
•Specifying V LANs to Moni tor, page 21-18
•Specifying V LANs to Filter, page 21-19

RSPAN Configuration Guidelines

Follow these guidelines when configuring RSPAN:
•All the items in the “SPAN Configuration Guidelines” section on page 21-8 apply t o RSPAN .
Note As RSPAN VLANs have special proper ties, yo u should reserve a few VLANs across you r network for
use as RSPAN VLANs; do not assign access ports to these VLANs.
Note You can apply an output access control list (ACL) to RSPAN traffic to selectively filter or monitor
specific packets. Specify these ACLs on the RSPAN VLAN in the RSPAN source switches.
•RSPAN sessions can coexist with SPAN sessions within the limits described in the “SPAN and
RSPAN Session Limits” section on page 21 -8.
•For RSPAN configuration, you can distribute the source ports and the destination ports across
multiple switches in your network.
•A port canno t serve as an RSPAN source port or RSPA N destin ation po rt while designate d as an
RSPAN reflector port.
•When you configure a switch port as a reflector port, it is no longer a normal switch port; only
looped-back traffic passes through the reflector port.
•RSPA N d oe s not su pport BPDU p acket monito ring or oth er L ayer 2 sw itch pr otocol s.
•The RSPAN VL AN is configured only on t runk ports a nd not on access po rts. To avoid unwanted
traffic in RSPAN VLANs, make sure that the VLAN remote-span feature is supported in all the
participating switches. Access ports on the RSPAN VLAN are silently disabled.
•RSPA N VLANs are included as sourc es for port-ba sed RSPAN sessions when source tru nk ports
have active RSPAN VLANs. RSPAN VLANs can also be sources in SPAN sessions.
•You can configure any VLAN as an RSPAN VLAN as long as these conditions are met:
–
No access port is configured in the RSPAN VLAN.
–
The same RSPAN VLAN is used for an RSPAN session in all the switches.
–
All participating switches support RSPAN.