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

The correct answer is D. UDP port 1701. L2TP uses UDP port 1701 as its default port. L2TP is a tunneling protocol used to support VPNs; it is connectionless and uses UDP rather than TCP because it relies on the upper-layer protocols (or IPSec) for reliability and security. For context: UDP 161 is SNMP, TCP 443 is HTTPS

Foundational Security Concepts

Question

Options

AUDP port 161
BTCP port 443
CTCP port 110
DUDP port 1701

How the community answered

(59 responses)

B
5% (3)
C
2% (1)
D
93% (55)

Explanation

L2TP uses UDP port 1701 as its default port. L2TP is a tunneling protocol used to support VPNs; it is connectionless and uses UDP rather than TCP because it relies on the upper-layer protocols (or IPSec) for reliability and security. For context: UDP 161 is SNMP, TCP 443 is HTTPS, TCP 110 is POP3. When L2TP is combined with IPSec (L2TP/IPSec), it also uses UDP ports 500 (IKE) and 4500 (NAT traversal), but the native L2TP port remains UDP 1701.

Topics

#L2TP#Network Ports#UDP#VPN Protocols

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