Command Line Reference Guide

Port Monitoring

The port monitoring feature allows you to monitor network traffic by forwarding a copy of each

incoming or outgoing packet from one port to another port.

Important Points to Remember

• Port monitoring is supported on physical ports only. Port-channel interfaces and virtual local area

networks (VLANs), are not supported.

• The monitoring (destination, “MG”) and monitored (source, “MD”) ports must be on the same switch.

• The monitored (source) interface must be a server-facing interface in the format slot/port, where valid

slot numbers are 0-1 and server-facing port numbers are from 1 to 32. The monitoring interface must

be an uplink port in the chassis.

• Dell Networking OS permits a limited set of commands for monitoring ports. To display these

commands, use the ? command.

• Only one MG and one MD may be in a single port-pipe.

• A monitoring port may not be a member of a VLAN.

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

• A source port (MD) can only be monitored by one destination port (MG). If you try to assign a

monitored port to more than one monitoring port, the following error is displayed as shown in

example.

Example

Dell(conf)#mon ses 1

Dell(conf-mon-sess-1)#source tengig 0/0 destination tengig

0/60 direction both

Dell(conf-mon-sess-1)#do show mon ses

SessionID Source Destination Direction Mode Type

--------- ------ ----------- --------- ---- ----

1 TenGig 0/0 TenGig 0/60 both interface

Port-based

Dell(conf-mon-sess-1)#mon ses 2

Dell(conf-mon-sess-2)#source tengig 0/0 destination tengig

0/61 direction both

% Error: MD port is already being monitored.

NOTE: There is no limit to the number of monitoring sessions per system, provided that there are

only four destination ports per port-pipe. If each monitoring session has a unique destination port,

the maximum number of session is four per port-pipe.

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Port Monitoring