Which three of the following steps are mandatory when configuring MPLS on Cisco IOS? （）(Choose three.)

A. to make CEF tables smaller
B. to enable label switching on the frame mode interface
C. to restrict MPLS availability to predefined time periods
D. to restrict label switching to a limited number of networks
E. to restrict end users from seeing the routers in the MPLS network

A. If using IS-IS as the PE-CE routing protocol, no redistribution is required.
B. If using static routes between the CE and PE routers, no redistribution of other VPN routes is required.
C. If the PE-CE protocol is not BGP, redistribution of other VPN routes from MP-BGP is required.
D. If RIP is the routing protocol that is used between the PE-CE routers, no redistribution is required, but any other protocol will require redistribution.
E. If using OSPF or EIGRP as the PE-CE routing protocol, redistribution is not required, but any other protocol or static route will require redistribution.

A.data center
B.teleworker
C.branch
D.campus