Local Span And Rspan Sessions - Cisco 6500 Series Software Configuration Manual

Chapter 34 Configuring Local SPAN and RSPAN
RSPAN Overview
RSPAN supports source ports, source VLANs, and destination ports on different switches, which
provides remote monitoring of multiple switches across your network (see
each RSPAN session is carried over a user-specified RSPAN VLAN that is dedicated for that RSPAN
session in all participating switches.
The RSPAN source ports can be trunks carrying the RSPAN VLAN. Local SPAN and RSPAN do not
monitor the RSPAN traffic in the RSPAN VLAN seen on a source trunk.
The RSPAN traffic from the source ports or source VLANs is switched to the RSPAN VLAN and then
forwarded to destination ports, which are in the RSPAN VLAN. The sources (ports or VLANs) in an
RSPAN session can be different on different source switches but must be the same for all sources on each
RSPAN source switch. Each RSPAN source switch must have either ports or VLANs as RSPAN sources.
Figure 34-2 RSPAN Configuration
Layer 2 trunk
Switch A

Local SPAN and RSPAN Sessions

SPAN sessions (local or remote) allow you to monitor traffic on one or more ports, or one or more
VLANs, and send the monitored traffic to one or more destination ports.
A local SPAN session is an association of a set of source ports and source VLANs with one or more
destination ports. You configure a local SPAN session on a single network device. Local SPAN does not
have separate source and destination sessions.
RSPAN consists of an RSPAN source session, an RSPAN VLAN, and an RSPAN destination session.
You separately configure RSPAN source sessions and destination sessions on different network devices.
To configure an RSPAN source session on one network device, you associate a set of source ports and
VLANs with an RSPAN VLAN. To configure an RSPAN destination session on another device, you
associate the destination port with the RSPAN VLAN.
78-14099-04
Switch D
D1
Layer 2 trunk
C3
Switch C
C2
C1
A3
A1 A2
B1 B2
Catalyst 6500 Series Switch Cisco IOS Software Configuration Guide—Release 12.1 E
Understanding How Local SPAN and RSPAN Work
Destination switch
(data center)
D2
Probe
Intermediate switch
(distribution)
Layer 2 trunk
B4
Source switch(es)
Switch B
(access)
B3
Figure 34-2). The traffic for
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