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Catalyst 3750 Switch Software Configuration Guide
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Chapter 27 Configuring SPAN and RSPAN
Understanding SPAN and RSPAN
This section includes these topics:
• Local SPAN, page 27-2
• Remote SPAN, page 27-3
• SPAN and RSPAN Concepts and Terminology, page 27-4
• SPAN and RSPAN Interaction with Other Features, page 27-9
• SPAN and RSPAN and Switch Stacks, page 27-10
Local SPAN
Local SPAN supports a SPAN session entirely within one switch; all source ports or source VLANs and
destination ports reside in the same switch or switch stack. Local SPAN copies traffic from one or more
source ports in any VLAN or from one or more VLANs to a destination port for analysis. For example,
in Figure 27-1, all traffic on port 5 (the source port) is mirrored to port 10 (the destination port). A
network analyzer on port 10 receives all network traffic from port 5 without being physically attached
to port 5.
Figure 27-1 Example of Local SPAN Configuration on a Single Switch
Figure 27-2 is an example of a local SPAN in a switch stack, where the source and destination ports
reside on different stack members.
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Port 5 traffic mirrored
on Port 10
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Network analyzer
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