What are suitable protocols for securing VPN connections?

A.
S/MIME and SSH

B.
TLS and SSL

C.
IPsec and L2TP

D.
PKCS# and X.509

Explanation:
Both of them can be used to create and secure VPN’s. The Layer 2 Tunnel Protocol (L2TP) is an
emerging Internet Engineering Task Force (IETF) standard that combines the best features of two
existing tunneling protocols: Cisco’s Layer 2 Forwarding (L2F) and Microsoft’s Point-to-Point
Tunneling Protocol (PPTP). L2TP is an extension to the Point-to-Point Protocol (PPP), which is an

important component for VPNs. VPNs allow users and telecommuters to connect to their corporate
intranets or extranets. IPSec is a series of guidelines for the protection of Internet Protocol (IP)
communications. It specifies ways for securing private information transmitted over public networks.
Services supported by IPSec include confidentiality (encryption), authenticity (proof of sender),
integrity (detection of data tampering) and replay protection (defense against unauthorized resending of data). It work on layer 3 of the OSI model and is the most common protocols used to
create VPNs.