Users Guide

Conguring Remote Port Mirroring
Remote port mirroring requires a source session (monitored ports on dierent source switches), a reserved tagged VLAN for transporting
mirrored trac (congured on source, intermediate, and destination switches), and a destination session (destination ports connected to
analyzers on destination switches).
Conguration Notes
When you congure remote port mirroring, the following conditions apply:
• You can congure 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 trac by prexing the reserved VLAN tag to monitored packets so that they are
copied to the reserve VLAN.
• Mirrored trac 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.
• The RPM VLAN can’t be a Private VLAN.
• The RPM VLAN can be used as GVRP VLAN.
• The L3 interface conguration should be blocked for RPM 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 source session, the reserved VLAN can have at max of only 4 member ports.
• To associate with destination session, the reserved VLAN can have multiple member ports.
• Reserved Vlan cannot have untagged ports.
In the reserved L2 VLAN used for remote port mirroring:
• MAC address learning in the reserved VLAN is automatically disabled.
• The reserved VLAN for remote port mirroring can be automatically congured in intermediate switches by using GVRP.
• There is no restriction on the VLAN IDs used for the reserved remote-mirroring VLAN. Valid VLAN IDs are from 2 to 4094. The default
VLAN ID is not supported.
• In mirrored trac, packets that have the same destination MAC address as an intermediate or destination switch in the path used by
the reserved VLAN to transport the mirrored trac are dropped by the switch that receives the trac if the switch has a L3 VLAN
congured.
In a source session used for remote port mirroring:
• Maximum number of source sessions supported on a switch: 4
• Maximum number of source ports supported in a source session: 128
• You can congure physical ports and port-channels as sources in remote port mirroring and use them in the same source session. You
can use both Layer 2 (congured with the switchport command) and Layer 3 ports as source ports. You can optionally congure one or
more source VLANs to specify the VLAN trac to be mirrored on source ports.
• You can use the default VLAN and native VLANs as a source VLAN.
• You cannot congure the dedicated VLAN used to transport mirrored trac as a source VLAN.
• Egressing remote-vlan packets are rate limited to a default value of 100 Mbps.
In a destination session used for remote port mirroring:
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Port Monitoring