Which three attributes are advertised to the remote PE and BGP-based VPNs？（）

A.Both use LDP
B.Both use BGP
C.Both require additional hardware.
D.Both use a two-label stack for forwarding.

A.L2TP
B.2547bis
C.L2F
D.PPTP
E.MPLS

A.The default OSPF domain-id is 127.0.0.1.
B.It most cases， a domain-id must be configured.
C.It most cases， you do not need to configure a domain-id.
D.For a layer 3 VPN connecting multiple OSPF domains， configuring a domain-id can help control LSA translations.