Configuring Port Mirroring Instances

Layer 2 Port Mirroring Named Instances Overview

On an MX Series router and on an EX Series switch, you can define a set of port-mirroring properties that you can explicitly bind to physical ports on the router or switch. This set of port mirroring properties is known as a named instance of Layer 2 port mirroring.

You can bind a named instance of Layer 2 port mirroring to physical ports associated with an MX Series router’s or an EX Series switch’s Packet Forwarding Engine components at different levels of the router (or switch) chassis:

• At the FPC level—You can bind a named instance to the physical ports associated with a specific Dense Port Concentrator (DPC) or to the physical ports associated with a specific Flexible Port Concentrator (FPC).

• At the PIC level—You can bind a named instance of port mirroring to a specific Packet Forwarding Engine (on a specific DPC) or to a specific PIC.

The following points summarize the behavior of Layer 2 port mirroring based on named instances:

• The scope of packet selection is determined by the target of the binding—At the ports (or port) bound to a named instance of Layer 2 port mirroring, the router or switch selects input packets according to the packet-selection properties in the named instance.

• The destination of a selected packet is determined by the packet address family—Of the packets selected, the router or switch mirrors only the packets belonging to an address family for which the named instance of Layer 2 port mirroring specifies a set of mirror destination properties. In a Layer 2 environment, MX Series routers and EX Series switches support port mirroring of VPLS (family ethernet-switching or family vpls) traffic and Layer 2 VPN traffic with family ccc.

For a general description of Layer 2 port-mirroring properties, see Understanding Layer 2 Port Mirroring Properties. For a comparison of the types of Layer 2 port mirroring available on an MX Series router and on an EX Series switch, see Application of Layer 2 Port Mirroring Types.

Mirroring at Ports Grouped at the FPC Level

On an MX Series router and on an EX Series switch, you can bind a named instance of Layer 2 port mirroring to a specific DPC or FPC installed in the router (or switch) chassis. The port mirroring properties in the instance are applied to all Packet Forwarding Engines (and their associated ports) on the specified DPC or to all PICs (and their associated ports) installed in the specified FPC. Port mirroring properties that are bound to a DPC or FPC override any port-mirroring properties bound at the global level or the MX Series router (or switch) chassis.

Mirroring at Ports Grouped at the PIC Level

On an MX Series router and on an EX Series switch, you can bind a named instance of Layer 2 port mirroring to a specific Packet Forwarding Engine or PIC. The port-mirroring properties in that instance are applied to all ports associated with the specified Packet Forwarding Engine or PIC. Port-mirroring properties that are bound to a Packet Forwarding Engine or PIC override any port-mirroring properties bound at the DPC or FPC that contains them.

Mirroring at a Group of Ports Bound to Multiple Named Instances

On an MX Series router and on an EX Series switch, you can apply up to two named instances of Layer 2 port mirroring to the same group of ports within the router (or switch) chassis. By applying two different port-mirroring instances to the same DPC, FPC, Packet Forwarding Engine, or PIC, you can bind two distinct Layer 2 port mirroring specifications to a single group of ports.