Which of the following ports is the default port for Layer 2 Tunneling Protocol (L2TP) ?

A.
UDP port 161

B.
TCP port 443

C.
TCP port 110

D.
UDP port 1701

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 Pointto-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. UDP port 1701 is the default port for L2TP.
Answer option A is incorrect. UDP port 161 is the default port for Simple Network Management
Protocol (SNMP).

Answer option B is incorrect. TCP port 443 is the default port for Hypertext Transfer Protocol Secure
(HTTPS) and Secure Socket Layer (SSL).
Answer option C is incorrect. TCP port 110 is the default port for Post Office Protocol version 3
(POP3).
TechNet, Contents: ” Basic L2TP/IPSec Troubleshooting in Windows 2000 [Q259335]”