C H A P T E R
7
Configuring Traffic Mirroring
This module describes the configuration of the traffic mirroring feature. Traffic mirroring is sometimes called
port mirroring, or switched port analyzer (SPAN).
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Overview of Traffic Mirroring, on page 95
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Traffic Mirroring Terminology, on page 97
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Characteristics of the Source Port, on page 98
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Characteristics of the Monitor Session, on page 98
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Characteristics of the Destination Port, on page 98
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Configure Traffic Mirroring, on page 99
Overview of Traffic Mirroring
Traffic mirroring, which is sometimes called port mirroring, or Switched Port Analyzer (SPAN) is a Cisco
proprietary feature that enables you to monitor network traffic passing in, or out of, a set of ports. You can
then pass this traffic to a destination port on the same router.
Traffic mirroring copies traffic from one or more source ports and sends the copied traffic to one or more
destinations for analysis by a network analyzer or other monitoring device. Traffic mirroring does not affect
the flow of traffic on the source interfaces or sub-interfaces, and allows the mirrored traffic to be sent to a
destination interface or sub-interface.
For example, you need to attach a traffic analyzer to the router if you want to capture Ethernet traffic that is
sent by host A to host B. All other ports see the traffic between hosts A and B.
Interface and Hardware Component Configuration Guide for Cisco NCS 6000 Series Routers, IOS XR Release 6.4.x
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