Which
of the following protocols provides certificate-based authentication for virtual private networks
(VPNs)?
A.
PPTP
B.
SMTP
C.
HTTPS
D.
L2TP
Explanation:
Layer 2 Tunneling Protocol (L2TP) is a more secure version of Point-to-Point Tunneling
Protocol (PPTP). It provides tunneling, address
assignment, and authentication. L2TP allows transfer of Point-to-Point Protocol (PPP) traffic
between different networks. L2TP combines with
IPSec to provide both tunneling and security for Internet Protocol (IP), Internetwork Packet Exchange
(IPX), and other protocol packets across
IP networks. It provides certificate-based authentication for virtual private networks (VPNs).
Answer option A is incorrect. Point-to-Point Tunneling Protocol (PPTP) is a remote access protocol.
It is an extension of the Point-to-Point
Protocol (PPP). PPTP is used to securely connect to a private network by a remote client using a
public data network, such as the Internet.
Virtual private networks (VPNs) use the tunneling protocol to enable remote users to access
corporate networks securely across the Internet.
PPTP supports encapsulation of encrypted packets in secure wrappers that can be transmitted over a
TCP/IP connection.
Answer options C and B are incorrect. The HTTPS and SMTP protocols are not used in virtual private
networks (VPNs).