L2TP is short for the Layer Two Tunneling Protocol, and it is built into the majority of operating systems and devices as well. It's an extension to something that's called a PPP protocol, and it also merges two of the finest protocols known as L2F and PPTP. L2TP is mostly used to provide support to VPN services. On its own, L2TP doesn’t ensure powerful encryption or authentication, and that's why it's used along with the superb IPSec tunneling protocol. IPSec is a great protocol that is used for encrypting every IP packet in a communication between two devices. With the IPSec, the VPN connection is completely secure. When combined, these two protocols make the superb L2TP/IPSec VPN protocol.
We’ll help you to get familiar with this VPN protocol by providing you information regarding how it works, its pros and cons, and so on.
1. What is L2TP?
L2TP is a tunneling protocol that was made for the purpose of supporting the connection of VPNs. There are a lot of Internet Service Providers that use this VPN protocol so they could allow VPN service operations. It was developed back in 1999 by Cisco Systems and Microsoft.
2. How does L2TP work?
L2TP begins by making a connection between two of its endpoints. They are known as LNS or the L2TP Network Server and the LAC, which stands for L2TP Access Concentrator. LAC is a device whose purpose is to physically terminate a call. Meanwhile, the goal of the LNS is terminating the PPP stream. LNS could potentially authenticate this stream as well. PPP is short for Point-to-Point protocol. This is a layer 2 or data link layer protocol that transmits data between two routers.
PPP is afterward enabled, encapsulated, and carried over the Internet. Then, the connection of this L2 link layer is made by you with the help of your Internet Service Provider. When the connection is granted thanks to the L2TP Access Concentrator, the PPP Link will be made. Then, an open slot in the tunnel of the network is created, and the request goes to the L2TP Network Server.
Then, the very moment the connection is accepted, a PPP Interface will be created. Afterward, link frames can pass through the network tunnel without any complications. LNS is going to allow these link frames. Then, the LNS will remove the encapsulation of the Layer Two Tunneling Protocol, and it will process those link frames like normal ones.
3. How to set up L2TP/IPSec on your VPN?
We will use an example of one of the most popular VPNs on the market, ExpressVPN. As you probably know, a VPN protocol is a way with which your device (laptop, PC, tablet, or smartphone) is going to connect to a Virtual Private Network Server. If you want to set up the L2TP/IPSec protocol on your device, first click the hamburger menu. Then, you should go to Options.
You will see the Protocol tab. Click on the L2TP/IPSec and click OK. This VPN protocol is very useful for protecting your online anonymity and changing VPN locations. Probably, the only downside of this VPN protocol is that the security is not that strong.
4. L2TP Security
When the LT2P is compared to the PPTP protocol, it's considered as the superior one. L2TP doesn't have any encryption, so it would be wise if you don't use it when you're on the Internet. This is the reason why the LSTP is combined with the strong IPSec protocol. It uses 256-bit AES encryption as well as double encapsulation that could secure your info even better.
First, your Internet traffic is going to be encapsulated just as a usual PPTP connection, and the IPSec will encapsulate your Internet traffic for the second time. Rumors say that cyber-criminals have hacked LSTP/IPSec on multiple occasions. Edward Snowden even claims that that the National Security Agency or the NSA has significantly weakened this tunneling protocol, but there are no solid proofs.
We think that the L2TP/IPSec is safe for VPN users. Nonetheless, you should probably subscribe to a VPN service that has a no-logs policy. This way, the authorities won’t be able to get ahold of your information even if they wanted to, because the VPN will keep no logs.
5. L2TP Speed
This tunneling is quite fast given the fact that it uses zero encryption. But, the major disadvantage is that you won’t have secure VPN connections. Users who prefer speed over security should choose this VPN protocol.
Regarding the LSTP/IPSec protocol, it has pretty good connection speeds, but it would really be great if you had a strong CPU ( Central Processing Unit) and a broadband connection of 100 Mbps, at least. If not, there might be slight variations in speed, but not too significant.
6. Pros and Cons
Like many other tunneling protocols, the L2TP has its advantages and disadvantages.
- You can combine it with IPSec to have better security
- Easy to set up
- Built into Windows
- Has no encryption, so you should combine it with IPSec
Apart from the OpenVPN protocol, the L2TP/IPSec is the strongest tunneling protocol. It's reliable, fast, and safe to use. Choose this tunneling protocol for your VPN.