Port Management 
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3.2 Port Mirroring 
3.2.1 Overview 
The function of port mirroring provided by the switch realizes the data duplication from one 
or several ports (the source mirroring ports) to the specified port (the mirroring destination 
port).  The  data  monitoring  equipment  connected  with  the  destination  port  enables  the 
network administrator to monitor the traffic, analyze the performance and diagnose the fault 
real-timely. 
  The Basic Concept of Port Mirroring 
1. Source Port 
As the ports monitored, users are allowed to monitor and analyze the message passing 
through the source port. All messages’ monitor can be achieved on the condition that the 
source port is set as a routed port (i.e. the port accessing to the Internet). 
2. Mirroring Destination Port 
The  mirroring  destination  port,  called  monitor  port  as  well,  monitors  and  analyzes  the 
messages by forwarding the received ones to the data monitoring equipment. 
The speed of mirroring destination port is bound to be not less than the all ports combined. 
3. Mirroring Direction 
Three kinds of mirroring port directions are listed below. 
  Receiving  direction:  the  mirroring  is  specific  to  the  messages  received  through  the 
source ports. 
  Sending direction: the mirroring aims at the messages sent by the source ports. 
  Sending and receiving direction: both the messages received and sent by the source 
ports. 
Tip 
The duplication of the same data flow is processed only once by the switch. For example, 
when the port 5 conducts mirroring of port 1 in the receiving direction and port 2 in the 
sending direction, port 5 only gives one mirroring to the message forwarded to the port 2 by 
port 1.