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Catalyst 3750-X and 3560-X Switch Software Configuration Guide
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Chapter 32 Configuring SPAN and RSPAN
Understanding SPAN and RSPAN
Figure 32-3 Example of RSPAN Configuration
SPAN and RSPAN Concepts and Terminology
SPAN Sessions, page 32-4
Monitored Traffic, page 32-6
Source Ports, page 32-7
Source VLANs, page 32-7
VLAN Filtering, page 32-7
Destination Port, page 32-8
RSPAN VLAN, page 32-9

SPAN 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 destination port with source ports or source VLANs, all on
a single network device. Local SPAN does not have separate source and destination sessions. Local
SPAN sessions gather a set of ingress and egress packets specified by the user and form them into a
stream of SPAN data, which is directed to the destination port.
RSPAN
VLAN
RSPAN
source ports RSPAN
source ports
RSPAN
destination ports
RSPAN
source
session B
Intermediate switches
must support RSPAN VLAN
Switch B
RSPAN
destination
session
Switch C
RSPAN
source
session A
Switch A
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