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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 EMC 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:
• Port Monitoring
• Configuring Monitor Multicast Queue
• Remote Port Mirroring
• Encapsulated Remote Port Monitoring
• Port Monitoring on VLT
Port Monitoring
Port monitoring is supported on both physical and logical interfaces, such as VLAN and port-channel interfaces. The source port
(MD) with monitored traffic and the destination ports (MG) to which an analyzer can be attached must be on the same switch.
You can configure up to 128 source ports in a monitoring session. Only one destination port is supported in a monitoring session.
The platform supports multiple source-destination statements in a single monitor session.
The maximum number of source ports that can be supported in a session is 128.
The maximum number of destination ports that can be supported depends on the port mirroring directions as follows:
● 4 per port pipe, if the four destination ports mirror in one direction, either rx or tx.
● 2 per port pipe, if the two destination ports mirror in bidirection.
● 3 per port pipe, if one of the destination port mirrors bidirection and the other two ports mirror in one direction (either rx or
tx).
In the following examples, ports 1/13, 1/14, 1/15, and 1/16 all belong to the same port-pipe. They are pointing to four different
destinations (1/1, 1/2, 1/3, and 1/37). Now it is not possible for another source port from the same port-pipe (for example, 1/17)
to point to another new destination (for example, 1/4). If you attempt to configure another destination (to create 5 MG port),
this message displays: % Error will be thrown in case of RPM and ERPM features.
Example of Changing the Destination Port in a Monitoring Session
Example of Configuring Another Monitoring Session with a Previously Used Destination Port
Example of Viewing a Monitoring Session
In the example below, 0/25 and 0/26 belong to Port-pipe 1. This port-pipe has the same restriction of only four destination
ports, new or used.
Given these parameters, the following illustration shows the possible port monitoring configurations.
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