Help us improve your experience.

Let us know what you think.

Do you have time for a two-minute survey?

Configuring Local Interface Switching in Layer 2 Circuits

 

You can configure a virtual circuit entirely on the local router, terminating the circuit on a local interface. Possible uses for this feature include being able to enable switching between Frame Relay DLCIs.

To configure a virtual circuit to terminate locally, include the local-switching statement:

You can include this statement at the following hierarchy levels:

  • [edit protocols l2circuit]

  • [edit logical-systems logical-system-name protocols l2circuit]

    Note

    ACX Series routers do not support the [edit logical-systems] hierarchy level.

The following sections describe how to configure local interface switching:

Configuring the Interfaces for the Local Interface Switch

Local interface switching requires you to configure at least two interfaces:

  • Starting interface—Include the interface statement at the [edit protocols l2circuit local-switching] hierarchy level.

  • Ending interface—Include the end-interface statement at the [edit protocols l2circuit local-switching interface interface-name] hierarchy level.

You can also configure virtual circuit interface protection for each local interface:

  • Protect interface for the starting interface—Include the protect-interface statement at the [edit protocols l2circuit local-switching interface interface-name] hierarchy level.

  • Protect interface for the ending interface—Include the protect-interface statement at the [edit protocols l2circuit local-switching interface interface-name end-interface] hierarchy level.

For more information about how to configure protect interfaces, see Configuring the Protect Interface.

Typically, when the primary interface goes down, the pseudowire starts using the protect interface. By default, when the primary interface comes back online, the interface is switched-over back from the protect interface to the primary interface. To prevent the switchover back to the primary interface, unless the primary interface goes down, include the no-revert statement. This prevents loss of traffic during the switchover.

Note

If the protect interface fails, the interface is switched-over back to the primary interface, irrespective of whether or not the no-revert statement is included in the configuration.

You can configure the no-revert statement both for the starting interface and the ending interface.

Note

The protect interface must be configured prior to configuring the no-revert statement.

Enabling Local Interface Switching When the MTU Does Not Match

You can configure a local switching interface to ignore the MTU configuration set for the associated physical interface. This enables you to bring up a circuit between two logical interfaces that are defined on physical interfaces with different MTU values.

To configure the local switching interface to ignore the MTU configured for the physical interface, include the ignore-mtu-mismatch statement:

You can include this statement at the following hierarchy levels:

  • [edit protocols l2circuit local-switching interface interface-name]

  • [edit logical-systems logical-system-name protocols l2circuit local-switching interface interface-name]

    Note

    ACX Series routers do not support the [edit logical-systems] hierarchy level.