Bridging with GRE
A limitation of a regular GRE-encapsulated tunnel is that the resulting tunnels cannot be added to a bridge group. GRE for bridging provides this ability. Use GRE for bridging only in cases in which tunnel interfaces are to be included in a bridge group.
To configure GRE for bridging, use the gre-bridge option of the interfaces tunnel encapsulation command. For more information about using bridging, refer to Ciena Vyatta Network OS Bridging Configuration Guide.