A.1
B.None
C.3
D.2
E.It depends on the numbers of hops between the ingress and egress PE

A.Provider support for intra-AS and CSC scenarios
B.Uses separate signaling plane， which provides more security than IPv4
C.BGP is the preferred routing protocol for connecting two SPs
D.No requirement for a separate signaling plane

A.The MDT group address should be the same for both address families in the same VRF
B.The MDT group address should be the same for both address families in the different VRFs
C.Configuration of the MDT source on a pre-VRF basis is supported only on IPv6
D.The MDT group address should be different for both address families in the same VRF

A.GRE tunnels
B.automatic 6 to 4 tunnels
C.ISATAP tunnels
D.manual tunnels （RFC 2893）

A.MPLS is enabled on the core， distribution， and edge devices.
B.A triple stack is enabled on PE devices.
C.The network has at least six PE devices.
D.A dual stack is enabled on all the P and PE devices in a network.