Which of the following is less likely to be used in creating a Virtual Private Network?

A.
L2TP

B.
PPTP

C.
IPSec

D.
L2F

Explanation:
“The following are the three most common VPN communications protocol standards: Point-to-Point
Tunneling Protocol(PPTP). PPTP works at the Data Link Layer of the OSI model. Designed for

individual client to server connections, it enables only a single point-to-point connection per session.
This standard is very common with asynchronous connections that use Win9x or NT clients. PPTP
uses native Point-to-Point Protocol (PPP) authentication and encryption services. Layer 2 Tunneling
Protocol (L2TP). L2TP is a combination of PPTP and the earlier Layer 2 Forwarding (L2F) Protocol that
works at the Data Link Layer like PPTP. It has become an accepted tunneling standard for VPN’s. In
fact, dial-up VPNs use this standard quite frequently. Like PPTP, this standard was designed for single
point-to-point client to server connections. Not that multiple protocols can be encapsulated within
the L2TP tunnel, but do not use encryption like PPTP. Also, L2TP supports TACACS+ and RADIUS, but
PPTP does not. IPSEC. IPSec operates at the Network Layer and it enables multiple and simultaneous
tunnels, unlike the single connection of the previous standards. IPSec has the functionality to
encrypt and authenticate IP data. It is built into the new Ipv6 standard, and is used as an add-on to
the current Ipv4. While PPTP and L2TP are aimed more at dial-up VPNs, IPSec focuses more on
network-tonetwork connectivity.” Pg. 123-125 Krutz: The CISSP Prep Guide: Gold Edition.