Administrator Guide

The reserved VLANs transport the mirrored traffic in sessions (blue pipes) to the destination analyzers in the local network. Two
destination sessions are shown: one for the reserved VLAN that transports orange-circle traffic; one for the reserved VLAN that
transports green-circle traffic.
Figure 118. Remote Port Mirroring
Configuring Remote Port Mirroring
Remote port mirroring requires a source session (monitored ports on different source switches), a reserved tagged VLAN for
transporting mirrored traffic (configured on source, intermediate, and destination switches), and a destination session
(destination ports connected to analyzers on destination switches).
Configuration Notes
When you configure remote port mirroring, the following conditions apply:
● You can configure any switch in the network with source ports and destination ports, and allow it to function in an
intermediate transport session for a reserved VLAN at the same time for multiple remote-port mirroring sessions. You can
enable and disable individual mirroring sessions.
● BPDU monitoring is not required to use remote port mirroring.
● A remote port mirroring session mirrors monitored traffic by prefixing the reserved VLAN tag to monitored packets so that
they are copied to the reserve VLAN.
● Mirrored traffic is transported across the network using 802.1Q-in-802.1Q tunneling. The source address, destination
address and original VLAN ID of the mirrored packet are preserved with the tagged VLAN header. Untagged source packets
are tagged with the reserve VLAN ID.
● You cannot configure a private VLAN or a GVRP VLAN as the reserved RPM VLAN.
● The L3 interface configuration should be blocked for the reserved VLAN.
● The member port of the reserved VLAN should have MTU and IPMTU value as MAX+4 (to hold the VLAN tag parameter).
● To associate with a source session, the reserved VLAN can have a maximum of 4 member ports.
Port Monitoring
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