3com WX3000 Manuel D’Utilisation

 

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VLAN-based mirroring: a device copies packets of a specified VLAN to the destination port. 

In local port mirroring, packets passing through one or more source ports of a device are copied to the 

destination port on the same device for packet analysis and monitoring. In this case, the source ports 

and the destination port must be located on the same device. 

Remote port mirroring does not require the source and destination ports to be on the same device. The 

source and destination ports can be located on multiple devices across the network. Therefore, 

administrators can monitor the traffic on remote devices conveniently. 

To implement remote port mirroring, a special VLAN, called remote-probe VLAN, is needed. All mirrored 

packets are sent from the reflector port of the source switch to the monitor port (destination port) of the 

destination switch through the remote-probe VLAN, so as to implement the monitoring of packets 

received on and sent from the source switch on the destination switch. 

implementation of remote port mirroring. 

Figure 1-2 Remote port mirroring application 

Reflector port

Source Port

Trunk port 

Destination port 

Remote-probe VLAN

Intermediate  Switch

Source 

Switch

Destination 

Switch

 

 

The switches involved in the remote port mirroring implementation play the following three roles. 

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Source switch: The monitored port resident switch. It copies traffic to the reflector port, which then 

transmits the traffic to an intermediate switch or destination switch through the remote-probe 

VLAN. 

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Intermediate switch: Switches between the source switch and destination switch on the network. 

An intermediate switch forwards mirrored traffic flows to the next intermediate switch or the 

destination switch through the remote-probe VLAN. No intermediate switch is present if the source 

and destination switches directly connect to each other. 

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Destination switch: The remote mirroring destination port resident switch. It forwards mirrored 

traffic flows it received from the remote-probe VLAN to the monitoring device through the 

destination port. 

 describes how the ports on various switches are involved in the mirroring operation.