Layer Two Tunneling Protocol (L2TP) is a tunneling protocol used by both Virtual Private Networks (VPN’s) and ISP’s. VPN’s use it for their connectivity, while ISP’s use it to facilitate VPN operations. The L2TP is the aftermath of the hybridization of two older protocols; the Microsoft Point-to-point Tunneling Protocol and the Cisco Layer 2 Forwarding Protocol.The L2TP took its features and functionalities from the above protocols and improved them significantly. It was published around the beginning of the 20th century to replace the above protocols and became the standard RFC 2661 that one of the most popular provider like NordVPN @ Globalwatchonline.sl uses.
What you need to know about the L2TP
- L2TP must be paired with another protocol for maximum use and benefit
- It is usually paired with the IPSec protocol, which acts as a security for data payload.
- The pairing of L2TP with IPSec opens up unlimited security possibilities, making it possible to use the best encryption keys, such as the AES 256-bit and the 3DES algorithm.
- Although L2TP’s dual encapsulation provides more security, it is also more resource intensive.
- Most often, L2TP uses the TCP port 1701. But once it is paired with the IPSec, it uses different ports: it uses the UDP port 500 for Internet Key Exchange (IKE), the 4500 for NAT, and 1701 for L2TP traffic when you are using Nord VPN @ Indonesia.
Below is an overview of the structure of the L2TP data packet:
- IP Header
- IPSec ESP Header
- UDP Header
- L2TP Header
- PPP Header
- PPP Payload
- IPSec ESP Trailer
- IPSec Authentication Trailer
How does the L2TP work?
The L2TP has two endpoints on the Internet: the L2TP Access Concentrator (LAC) and the L2TP Network Server (LNS). These are the points between which L2TP tunneling occurs. The first step in L2TP tunneling is to establish a connection between the two endpoints mentioned above. When this connection is active, a PPP layer is enabled and encapsulated. This is what is later moved around the web. The next step is to initiate the PPP connection using the ISP. Next, the LAC accepts the connection, establishing the PPP connection. A free slot is then allocated within the Network Tunnel, and the request is passed to the LNS. When the connection is thoroughly authenticated and accepted, a virtual PPP interface is createdëer. Once this is done, link frames can flow freely through the tunnel. The final aspect of the L2TP happens at the endpoint of the LNS. This is the processing of the frames once they are accepted, and L2TP encapsulation is removed for the top 10 najlepszy vpn @ Globalwatchonline.PL