Usage Scenario
On a BD scenario, the Router has two sub-interfaces configured in a main interface, one with the Dot1q encapsulation type and the other with the default encapsulation type. Once the sub-interface encapsulated Dot1q receives traffic, the sub-interface with the default encapsulation type also sends out the traffic. This may cause the illusion of return current. Besides, the Router has two interfaces configured on a BD scenario. The first interface has a sub-interface that is configured with the Dot1q encapsulation type. The second interface has two sub-interfaces that are configured with the Dot1q and default encapsulation types respectively. Once traffic passes through the sub-interface on the first interface, the second interface also sends two copied traffic from each of its sub-interfaces. This causes traffic to be replicated, wasting resources and reducing the board's forwarding efficiency. To allow traffic to be sent through specific interfaces, enable strict filter.
Run the command ethernet egress-strict-filter enable to enable the global strict filter function. The traffic that was previously forwarded through multiple interfaces is only forwarded through the EVC sub-interfaces with the Dot1q encapsulation type.