Translated by
2016/09/08 15:45:58

Layer 2 Tunneling Protocol (L2TP)

The tunneling protocol 2 levels (Layer 2 Tunneling Protocol) appeared in 1999. It integrates in itself(himself) a part of PPTP attributes and a part of L2F attributes (the proprietary Cisco protocol).

For 2016 L2TP is built in all modern operating systems and VPN compatible devices, and can be also easily configured, as well as the PPTP protocol (the same client is usually used). Problems can arise that L2TP uses UDP port 500 which can be blocked by a firewall if you are for NAT. Therefore additional setup of the router (readdressing of ports) can be required. While, the SSL protocol, for example, uses TCP port 443 to be indistinguishable from normal HTTPS traffic.

L2TP in itself does not provide confidentiality or strict authentication so usually works together with IPsec.

See Also