L2TP is shorthand for “Layer 2 Tunneling Protocol.” It is an extension of the commonly-used “Point-to-Point Tunneling Protocol” (PPTP) in VPNs. L2TP is not an encryption method on its own. It uses PPTP’s encryption. Your internet service provider uses PPTP to facilitate a VPN connection over the World Wide Web. It combines L2F by Cisco Systems and PPTP by Microsoft to get the most out of these two tunneling protocols.
The two elements that are comprised in L2TP are LNS (the L2TP Network Server) and LAC (the L2TP Access Concentrator). LNS is a device that cuts off and validates the PPP stream, whilst the LAC physically aborts a call. PPP determines the encapsulation channel that conveys multiprotocol data packets over Layer 2 point-to-point links. Normally, you connect to NAS (Network Access Server) via services that run PPP over this connection e.g. dial-up POTS, ADSL, or ISDN. In such a configuration, both PPP sessions and the Layer 2 are on the same Network Access Server.
Through packet-switched connections, L2P2 is able to locate endpoints on different devices. You, therefore, get a Layer 2 connection to the Access Concentrator that gives a subway for individual PPP frames to connect to NAS.
As such, data packets are processed independently from the circuit termination location. This tells you that the connection can recess at the local circuit concentrator and prevent long-distance charges. You may not notice an operational difference, but there are a lot of benefits involved.
Are you still wondering what is L2TP? Besides bringing together the best features of Cisco’s L2F and Microsoft’s PPTP, it also uses IPSec to secure your connections. Do you know why it is popular among internet users? It is considered an advanced version of the PPTP (a typical VPN protocol and encryption on most Microsoft platforms).
What’s more, it utilizes AES-256 bit and 3DES encryptions to encode your internet traffic. These encryption methods are two of the safest ways that companies and government agencies use to secure sensitive data.
How does it work?
The L2TP protocol improves the function of PPP. Normally, PPP predisposes data packets to various vulnerabilities as they travel from the client to the server. On the other hand, information that flows through L2TP consists of L2TP header on each packet. These packets are decrypted upon reception. As you can see, extra work is involved, and so L2TP performance is reduced. The trade-off is a highly secure data transmission. So, L2TP is a low-speed but highly secure VPN protocol.
What are the benefits and drawbacks of L2TP?
Every VPN protocol comes with a positive and negative side. The same thing applies to Layer 2 tunneling protocol. To get the most out of L2TP, you should know its pros and cons. The greatest advantage is that it supports a broad array of operating systems for desktop and mobile phones. Thanks to a native support, anyone can configure L2TP whether they have prior experience or not. Moreover, it uses powerful encryption standards, ensuring intact data integrity.
Looking at the other end of the spectrum, L2TP VPN is more complicated compared to OpenVPN protocols, making it hard to configure with NAT routers on most devices. Regardless, rumors have it that it’s breakable by government agencies who want to access certain traffic. The slower speed imposed by double encapsulation of L2TP is probably the biggest drawback. Overall, L2TP is a great option for VPN since it has the ideal balance between performance and online security.
What ports should you open to allow L2TP over IPsec VPN?
To allow VPN tunnels between networks or computers with firewall, there are various LT2P ports you need to open.
- The first one is the UDP 1701 which enables the flow of L2TP traffic.
- You also need to allow IKE (Internet Key Exchange) by opening the UDP 500.
- Lastly, open the UDP 5500 to facilitate NAT-T (IPSec Network Address Translation).
It is worth noting that PPTP requires TCP 1723 for maintenance traffic as well as Protocol ID 47 for the tunneled information to go through the router.
Protecting your online identity and privacy
Do you want to surf the internet safely and confidentially? Try a free L2TP VPN. You can even gain access to blocked sites and bypass censorship. VPN services that use AES-256 are known to provide some of the safest connections. L2TP uses IPsec for encryption. Although somewhat outdated, it is still secure enough for most uses. Thankfully, it is all natively supported by Mac, Android, and Windows.
Are IPsec and L2TP one and the same thing?
L2TP vs IPsec creates a common dilemma among VPN users. Cisco IPsec in tunnel mode doesn’t come with extra encapsulation. It establishes the tunnel through the IKE protocol. IKE has numerous authentication methods including Extended Authentication and Preshared keys. L2TP is rooted in PPTP. Since it doesn’t have strong authentication and encryption features, it is merged with IPsec. To reduce overhead, ESP in transport mode is included. In simple terms, the IPsec channel is created using IKE. The channel is then used to create an L2TP tunnel.
The IPsec network becomes the transportation mode for the L2TP encapsulated information. Unlike bare IPSec, the extra encapsulation layer provided by L2P2-L2TP header and IP/UDP packet makes it less effective with ESP in tunnel mode. NAT-T is quite problematic if used in conjunction with L2TP/IPsec because of ESP in transport mode. What makes L2TP VPN server better than plain IPsec is transporting other protocols besides the IP. In terms of security, L2TP and IPsec are equal. They differ in authentication mode, key strength, and algorithms.
What are the technical differences between L2TP, PPTP, and OpenVPN?
If you need a fast, reliable, and secure VPN connection, we recommend that you try L2TP, PPTP, or OpenVPN protocols. However, each one has its own strengths and weaknesses. Keep in mind that L2TP/IPsec supports an encryption level of up to 256-bit session keys. But the keys can differ depending on which algorithm is in place.
PPTP vs. OpenVPN
PPTP is a widely used VPN protocol. Its encryption level ranges up to 128-bit and is done with Microsoft Point-to-Point encryption. With PPTP, all you need is a username, password, and a virtual IP address to tap into a VPN server.
But it is not the safest or the most reliable VPN option and you might want to upgrade to L2TP. When it comes to compatibility, it is supported by Android, Apple, Linux, Windows, iOS, Mac, and Tomato.
OpenVPN is a popular open-source application for establishing VPN connections. It is more advanced than PPTP and supports 256-bit session keys, which may vary according to the algorithms used.
The encryption relies on OpenSSL library. When it comes to speed, it is faster compared to PPTP and L2TP/IPSec. OpenVPN is easy to install, highly reliable, and very stable.
Setting up VPN on a router with L2TP
You want to set up a VPN on a router that uses the L2TP protocol so you can connect any device to the VPN. If you encounter challenges with particular router models, we recommend that you contact your VPN provider for assistance. Also, you should check the compatibility of the router with your specific VPN because some VPNs don’t support routers. Without further ado, let’s get into the details.
Start by examining the specifications of your VPN client. You must sign into your account and click on the option that allows you to set up VPN for more devices. You might want to hire a professional to configure your router with the L2TP VPN. It is important that you access the router’s control panel or find a way to the router’s gateway. After the configuration, set up your password, save the details and connect to any server available on your VPN.