3Com Switch 4200G Configuration Guide

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CONFIGURATION FOR MIRRORING
FEATURES
Mirroring Features Mirroring refers to the process of copying packets that meet the specified rules to a
destination port. Generally, a destination port is connected to a data detect device,
which users can use to analyze the mirrored packets for monitoring and
troubleshooting the network.
Figure 76 Mirroring
Traffic Mirroring Uses ACLs to identify traffic flows and mirror packets that match to the destination
port.
Port Mirroring Port mirroring refers to the process of copying the packets received or sent by the
specified port to the destination port.
Remote Port
Mirroring—RSPAN
Remote switched port analyzer (RSPAN) refers to remote port mirroring. It eliminates
the limitation that the mirrored port and the mirroring port must be located on the
same switch. This feature makes it possible for the mirrored port and the mirroring
port to be located across several devices in the network, and facilitates the network
administrator to manage remote switches.
The application of RSPAN is illustrated in Figure 76:
Figure 77 RSPAN application
There are three types of switches with the RSPAN enabled.
■ Source switch: the switch to which the monitored port belongs.
Destination port
Data detect device
PC
Netw ork
Destination port
Data detect device
PC
Netw ork
Source
Switch
Intermediate Switch
Destination
Switch
Reflector port
Source Port
Trunk port
Destination port
Remote-probe VLAN
Source
Switch
Intermediate Switch
Destination
Switch
Reflector port
Source Port
Trunk port
Destination port
Remote-probe VLAN