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PORT MIRRORING CONFIGURATION
When configuring port mirroring, go to these sections for information you are 
interested in:
■ “Introduction to Port Mirroring” on page 895
■ “Configuring Local Port Mirroring” on page 897
■ “Configuring Remote Port Mirroring” on page 898
■ “Displaying and Maintaining Port Mirroring” on page 899
■ “Port Mirroring Configuration Examples” on page 900
Introduction to Port 
Mirroring
Port mirroring allows you to duplicate the packets passing specified ports to the 
destination mirroring port. As destination mirroring ports usually have data 
monitoring devices connected to them, you can analyze the packets duplicated to 
the destination mirroring port on these devices so as to monitor and troubleshoot 
the network.
Figure 263   A port mirroring implementation
 
Classification of Port
Mirroring
There are two kinds of port mirroring: local port mirroring and remote port 
mirroring.
■ Local port mirroring copies packets passing through one or more ports (known 
as source ports) of a device to the monitor port (also destination port) for 
analysis and monitoring purpose. In this case, the source ports and the 
destination port are located on the same device.
■ Remote port mirroring implements port mirroring between multiple devices. 
That is, the source ports and the destination port can be located on different 
Host
Data monitoring device
Network
Source 
mirroring port
Destination 
mirroring port