3Com Switch 7750 Configuration Guide

686 CHAPTER 62: MIRRORING CONFIGURATION
Figure 179 Remote port mirroring application
There are three types of switches with remote port mirroring enabled.
■ Source switch: The switch to which the monitored port belongs. The source
switch copies the mirrored traffic flows to the remote-probe VLAN, and then
through Layer 2 forwarding, the mirrored flows are sent to an intermediate
switch or destination switch.
■ Intermediate switch: Switches between the source switch and destination
switch on the network. An intermediate switch forwards mirrored flows to the
next intermediate switch or the destination switch. Circumstances can occur
where no intermediate switch is present, if a direct connection exists between
the source and destination switches.
■ Destination switch: The switch to which the destination port for remote
mirroring belongs. It forwards mirrored flows it received from the remote-probe
VLAN to the monitoring device through the destination port.
Table 552 describes how the ports on various switches are involved in the
mirroring operation.
Table 552 Ports involved in the mirroring operation
Switch Ports involved Function
Source switch Source port Port to be mirrored; copy user data packets
to the specified reflector port through local
port mirroring. There can be more than one
source port.
Reflector port Receive user data packets that are mirrored
on a local port.
Relay port Send mirrored packets to the intermediate
switch or the destination switch.
You must set the port as a trunk port and
specify the port to permit packets of
remote-probe VLANs.
Intermediate
switch
Relay port Send mirrored packets to the destination
switch.
Two relay ports are necessary for the
intermediate switch to be connected to
devices that are connected to the source
switch and the destination switch.
You must set the port as a trunk port and
specify the port to permit packets of
remote-probe VLANs.
Reflector PortSource Port
Trunk Port
Destination Port
Remote-probe VLAN
Intermediate Switch
Source
Switch
Destination
Switch