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    Layer 2 Port Mirroring Named Instances

    This topic describes the following information:

    Layer 2 Port Mirroring Named Instances Overview

    On an MX Series router, you can define a set of port-mirroring properties that you can explicitly bind to physical ports on the router. 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 MX Series router Packet Forwarding Engine components at different levels of the router 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.

    Note: MX Series routers support DPCs as well as FPCs and PICs. Unlike FPCs, DPCs do not support PICs. In the Junos OS CLI, however, you use FPC and PIC syntax to configure or display information about DPCs and the Packet Forwarding Engines on the DPCs.

    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 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 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 support port mirroring of VPLS (family bridge 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, see Application of Layer 2 Port Mirroring Types.

    Mirroring at Ports Grouped at the FPC Level

    On an MX Series router, you can bind a named instance of Layer 2 port mirroring to a specific DPC or FPC installed in the router 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 chassis.

    Mirroring at Ports Grouped at the PIC Level

    On an MX Series router, 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.

    Note: For MX960 routers, there is a one-to-one mapping of Packet Forwarding Engines to Ethernet ports. Therefore, on MX960 routers only, you can configure port-specific bindings of port-mirroring instances.

    Mirroring at a Group of Ports Bound to Multiple Named Instances

    On an MX Series router, you can apply up to two named instances of Layer 2 port mirroring to the same group of ports within the router 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.

    Note: You can configure only one global instance of Layer 2 port mirroring on an MX Series router.

    Modified: 2017-08-31