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.
