Layer 2.5 injection of control traffic to ensure queuing on GRE tunnel with CoS settings intact

You can configure host-injected control traffic to reach the GRE tunnel interface queues at the packet forwarding engine when the control session is over the GRE tunnel interface. This includes control protocols OSPF, BGP, PIM, RSVP, LDP, OAM, BFD, and MSDP. Injection of control traffic ensures that the kernel includes the interface ID of the GRE logical interface and the unicast next-hop ID of the corresponding GRE physical interface along with the packet that is injected into the packet forwarding engine. With this feature enabled, all transit packets on the GRE tunnel logical interface have the ToS copied to the outer header. To enable this feature, configure the force-control-packets-on-transit-path statement on the GRE tunnel logical interface.