Cisco Systems 3750E manual Span and Rspan Concepts and Terminology, Span Sessions, 30-4

Chapter 30 Configuring SPAN and RSPAN

Understanding SPAN and RSPAN

Figure 30-3 Example of RSPAN Configuration

RSPAN

destination ports

Switch C	RSPAN
	destination
	session

Intermediate switches must support RSPAN VLAN

RSPAN

VLAN

Switch A

RSPAN source session A

Switch B

RSPAN source session B

RSPAN

RSPAN 101366

source ports

source ports

SPAN and RSPAN Concepts and Terminology

This section describes concepts and terminology associated with SPAN and RSPAN configuration.

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 consists of at least one RSPAN source session, an RSPAN VLAN, and at least one RSPAN destination session. You separately configure RSPAN source sessions and RSPAN destination sessions on different network devices. To configure an RSPAN source session on a device, you associate a set of source ports or source VLANs with an RSPAN VLAN. The output of this session is the stream of SPAN packets that are sent to the RSPAN VLAN. To configure an RSPAN destination session on another device, you associate the destination port with the RSPAN VLAN. The destination session collects all RSPAN VLAN traffic and sends it out the RSPAN destination port.

Catalyst 3750-E and 3560-E Switch Software Configuration Guide

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