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.