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.