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Catalyst 6500 Series Switch Software Configuration Guide—Release 8.7
OL-8978-04
Chapter 49 Configuring SPAN, RSPAN and the Mini Protocol Analyzer
Configuring RSPAN on the Switch
Figure 49-2
RSPAN Configuration
RSPAN Configuration Guidelines
This section describes the guidelines for configuring RSPAN:
Tip
As RSPAN VLANs have special properties, we recommend that you reserve a few VLANs across your
network for use as RSPAN VLANs. Do not assign an access port to these VLANs.
Tip
You can apply an output access control list (ACL) to the RSPAN traffic to selectively filter the specific
flows. Specify these ACLs on the RSPAN VLAN in the RSPAN source switches.
•
All the items in the
“SPAN Configuration Guidelines” section on page 49-7
apply to RSPAN.
•
The RSPAN sessions can coexist with the SPAN sessions within the SPAN/RSPAN limits that are
described in the
“SPAN, RSPAN and Mini Protocol Analyzer Session Limits” section on page 49-5
.
•
For the RSPAN configuration, you can distribute the source ports and the destination ports across
multiple switches.
•
For RSPAN, trunking is required if you have a source switch with all the source ports in one VLAN
(VLAN 2 for example) and it is connected to the destination switch through an uplink port that is
also in VLAN 2. With RSPAN, the traffic is forwarded to the remote switches in the RSPAN VLAN.
The RSPAN VLAN is configured only on trunk ports and not on access ports.
•
The learning option applies to the RSPAN destination ports only.
•
RSPAN does not support monitoring the BPDU packets or Layer 2 protocol packets such as Cisco
Discovery Protocol (CDP), Dynamic Trunking Protocol (DTP), and VLAN Trunking Protocol (VTP).
•
To optimize the bandwidth utilization in the connecting links, you can configure the quality of
service (QoS) parameters for the RSPAN VLAN in each of the participating source, intermediate,
or destination switches.
D1
D2
C1
C2
C3
A1
A2
A3
B1 B2
B4
B3
Switch A
Switch C
Switch D
Switch B
Probe
Destination switch
(data center)
Intermediate switch
(distribution)
Source switch(es)
(access)
27389
Layer 2 trunk
Layer 2 trunk
Layer 2 trunk