单项选择题
A.show bfd neighbor briefB.debug bfd packetC.debug bfd eventsD.show bfd neighbors detail
A.show ip backup routeB.show ip routeC.show ip interface briefD.show ip fast-reroute
A.show mpls traffic-eng tunnelsB.show tunnelC.show mpls traffic-eng fast-rerouteD.show mpls traffic-eng tunnels brief