An ERX Edge Router is operating in an MPLS network using interface label space.What is used to make a forwarding decision?（）

A. It performs a label pop operation and an IP lookup.
B. It performs a label swap operation and an IP lookup.
C. It sends an error message toward the egress router.
D. It sends an error message toward the ingress router.

A. egress router
B. ingress router
C. start of the bypass tunnel
D. all routers in the bypass tunnel

A. Only configured on the egress router
B. Only configured on the ingress router
C. Is pre-signalled to reduce packet loss
D. Must intersect the primary LSP at two locations