Users Guide

Port Monitoring

Port monitoring (also referred to as mirroring ) allows you to monitor ingress and/or egress traffic on

specified ports. The mirrored traffic can be sent to a port to which a network analyzer is connected to inspect

or troubleshoot the traffic.

Mirroring is used for monitoring Ingress or Egress or both Ingress and Egress traffic on a specific port(s). This

mirrored traffic can be sent to a port where a network sniffer can connect and monitor the traffic.

Dell Networking OS supports the following mirroring techniques:

• Port-Mirroring — Port Monitoring is a method of monitoring network traffic that forwards a copy of

each incoming and outgoing packet from one port of a network router to another port where the

packet can be studied.

• Remote Port Monitoring (RPM) — Remote Port Monitoring allows the user to monitor traffic running

across a remote device in the same network. Here the mirror traffic is carried over the L2 network, so

that probe devices in the network can analyze it. It is an extension to the normal Port Monitoring

feature. This feature is generally referred as RPM, where mirror traffic is carried over L2 network.

• Encapsulated Remote-Port Monitoring (ERPM) — ERPM is a feature to encapsulate mirrored packet

using GRE with IP delivery so that it can be sent across a routed network.

Topics:

• Important Points to Remember

• Port Monitoring

• Configuring Port Monitoring

• Configuring Monitor Multicast Queue

• Enabling Flow-Based Monitoring

• Remote Port Mirroring

• Encapsulated Remote Port Monitoring

• ERPM Behavior on a typical Dell Networking OS

Important Points to Remember

• Port Monitoring is supported on both physical and logical interfaces like virtual area network (VLAN) and

port-channel.

• The monitored (the source, [MD]) and monitoring ports (the destination, [MG]) must be on the same

switch.

• In general, a monitoring port should have no ip address and no shutdown as the only configuration; Dell

Networking OS permits a limited set of commands for monitoring ports. You can display these

commands using the ? command. A monitoring port also may not be a member of a VLAN.

• There may only be one destination port (MG) in a monitoring session.

• Source port (MD) can be monitored by more than one destination port (MG).

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