A.The LNS device receives the user's L2TP connection request, and can verify the user based on the user name and password

B.Remote users do not need to install VPN client software

C.After remote users access the Internet, they can directly initiate an L2TP tunnel connection request to the remote LNS through the client software

D.LNS assigns private IP addresses to remote users

A.IPv4 Session Table

B.NAPT related entries

C.IPSEC tunnel

D.Routing table

A.HTTPS

B.Telnet

C.FTP

D.SSH

A.Services and applications