erps vpls-subinterface enable

Usage Scenario

In normal situations, when the topology of an ERPS ring changes and an interface receives TC packets, the ERPS ring reselects an interface for blocking, and accordingly all devices update their ARP and MAC address entries. However, if an ERPS-enabled interface has sub-interfaces that are bound to VSIs, the sub-interfaces cannot detect the topology change immediately so that ARP and MAC entries will not be updated in time on the VPLS network. To prevent this problem, run the erps vpls-subinterface enable command to enable an ERPS-enabled interface to instruct its VSI-bound sub-interfaces to update ARP and MAC address entries after it receives TC packets.

Prerequisites

An interface has been added to an ERPS ring using the erps ring command.

Configuration Impact

After the erps vpls-subinterface enable command is run, when the forwarding status of an interface changes to Discarding, its VSI-bound sub-interfaces will change to the Flowdown state to prevent loops on the VPLS network on which a CE is dual-homed to PEs.

Services configured on the interface will be temporarily interrupted when you run the erps vpls-subinterface enable or undo erps vpls-subinterface enable command.

In an LDP VPLS or EVC VPLS scenario, after the erps vpls-subinterface enable command is run, the remote VPLS device clears the MAC address table when the ERPS network topology changes, regardless of the MAC-withdraw configuration.

Precautions

• The erps vpls-subinterface enable command is required only when an ERPS ring connects to a VPLS network through sub-interfaces.
• The erps vpls-subinterface enable and stp vpls-subinterface enable commands cannot be run on the same interface.
• If an interface is deleted from an ERPS ring using the undo erps ring command, the erps vpls-subinterface enable command configured on the interface is also deleted.