Users Guide

Remote port mirroring helps network administrators monitor and analyze traffic to troubleshoot network
problems in a time-saving and efficient way.
In a remote-port mirroring session, monitored traffic is tagged with a VLAN ID and switched on a user-
defined, non-routable L2 VLAN. The VLAN is reserved in the network to carry only mirrored traffic, which is
forwarded on all egress ports of the VLAN. Each intermediate switch that participates in the transport of
mirrored traffic must be configured with the reserved L2 VLAN. Remote port monitoring supports mirroring
sessions in which multiple source and destination ports are distributed across multiple switches
Remote Port Mirroring Example
Remote port mirroring uses the analyzers shown in the aggregation network in Site A.
The VLAN traffic on monitored links from the access network is tagged and assigned to a dedicated L2 VLAN.
Monitored links are configured in two source sessions shown with orange and green circles. Each source
session uses a separate reserved VLAN to transmit mirrored packets (mirrored source-session traffic is shown
with an orange or green circle with a blue border).
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