User manual

Publication ENET-UM001I-EN-P - January 2010 159
Troubleshoot an EtherNet/IP Module Chapter 11
Port Mirroring
Select a managed switch that supports port mirroring. With port mirroring,
you can direct frames being transmitted on one port to another port for
analysis by a traffic analyzer. Besides monitoring your Ethernet media
counters, port mirroring enables you to immediately spot anomalies in traffic
flow. A traffic analyzer can monitor the traffic on a given port and
troubleshoot a problem. Without port mirroring, you cannot see frames on
other ports. With hubs this is not an issue because all frames are transmitted
out all ports. The effective support and maintenance of Ethernet networks
often depends on reliable traffic analysis.
The benefits of port mirroring include:
• monitoring explicit messages betw
een controllers.
• monitoring implicit or I/O traffic.