CHAPTER
37-1
Software Configuration Guide—Release 12.2(25)SG
OL-7659-03
37
Configuring SPAN and RSPAN
This chapter describes how to configure the Switched Port Analyzer (SPAN) and Remote SPAN
(RSPAN) on the Catalyst4500 series switches. SPAN selects network traffic for analysis by a network
analyzer, such as a SwitchProbe device or other Remote Monitoring (RMON) probe.
This chapter consists of the following sections:
Overview of SPAN and RSPAN, page 37-1
Configuring SPAN, page 37-6
CPU Port Sniffing, page 37-10
Encapsulation Configuration, page 37-12
Ingress Packets, page 37-12
Access List Filtering, page 37-13
Packet Type Filtering, page 37-14
Configuration Example, page 37-15
Configuring RSPAN, page 37-16
Displaying SPAN and RSPAN Status, page 37-24
Note For complete syntax and usage information for the switch commands used in this chapter, refer to the
Catalyst 4500 Series Switch Cisco IOS Command Reference and related publications at
http://www.cisco.com/univercd/cc/td/doc/product/software/ios122/122cgcr/index.htm.

Overview of SPAN and RSPAN

This sections includes the following subsections:
SPAN and RSPAN Concepts and Terminology, page 37-3
SPAN and RSPAN Session Limits, page 37-6
Default SPAN and RSPAN Configuration, page 37-6
SPAN mirrors traffic from one or more source interfaces on any VLAN or from one or more VLANs to
a destination interface for analysis. In Figure37-1, all traffic on Ethernet interface 5 (the source
interface) is mirrored to Ethernet interface10. A network analyzer on Ethernet interface 10 receives all
network traffic from Ethernet interface 5 without being physically attached to it.