Reference Guide
Port Monitoring | 1177
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Port Monitoring
Overview
The Port Monitoring feature enables you to monitor network traffic by forwarding a 
copy of each incoming or outgoing packet from one port to another port. 
The commands in this chapter are generally supported on the C-Series, E-Series, and 
S-Series, with one exception, as noted in the Command History fields and by these 
symbols under the command headings: 
e E-Series, c C-Series, s S-Series, 
, or  . 
Commands
• description
• flow-based enable
• monitor session
• show config
• show monitor session
• show running-config monitor session
• source (port monitoring)
Important Points to Remember 
• On the E-Series, Port Monitoring is supported on TeraScale and ExaScale 
platforms.
• Port Monitoring is supported on physical ports only. Logical interfaces, such as 
Port Channels and VLANs, are not supported.
• A SONET port can only be configured as a monitored port.
• FTOS supports as many monitor sessions on a system as the number of 
port-pipes.
• The monitoring (destination, “MG”) and monitored (source, “MD”) ports must 
be on the same switch.










