Span And Rspan Concepts And Terminology; Span Sessions - Cisco Catalyst 3120 Software Manual

Understanding SPAN and RSPAN
Figure 29-3
must support RSPAN VLAN
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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.
Cisco Catalyst Blade Switch 3120 for HP Software Configuration Guide
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Example of RSPAN Configuration
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Chapter 29 Configuring SPAN and RSPAN
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