Your privacy comes first! The L2TP VPN protocol is an acronym for Layer Two Tunneling Protocol. ISPs use L2TP as an extension of the point-to-point protocol to enable and support VPNs. It is implemented with the IPSec tunneling protocol to further strengthen the connection as L2TP alone is not perfect. Thus, privacy and encryption will be provided for VPN functionality. IPsec helps in creating a secure channel that encapsulates L2TP traffic.
VPN protocols are like tunnels that add a layer of security around the data you send and receive. Because L2TP does not encrypt your content, your data needs an encryption protocol to pass through the tunnel, in order for your data to transit securely to its destination. In this article, you will learn what the L2TP VPN protocol is and what it is used for. To keep your connections secure and fast, it is a good idea to purchase Linux VPS or Mikrotik VPS services It enables you to configure your own VPN service.
What is the L2TP VPN protocol? You should know everything
In 1999/2000 the Layer Two Tunneling Protocol was published as the RFC 2661 protocol and developed by Microsoft and Cisco. It was also designed to replace the PTPP. L2TP is used to offer tunneling capabilities. Data transport is secure because it collects users’ content to send privately over public networks. L2TP is easy to implement and access so much support information available for it Online.
L2TP combines the best features of Point-to-Point Tunneling (PPTP) and Layer 2 Forwarding (L2F) protocols. LAC and LNC are the two core components that L2TP is made up of. Since L2TP is almost an old VPN protocol, it is not used as much as it was in the past. It doesn’t even support NordVPN anymore.
How does L2TP work?
The data line layer is called L2 and Network layer is called L3. L2 and L3 refer to the second and third layers of a seven-layer OSI model. Over an IP network or L3 network, L2TP allows the tunneling of L2 traffic. L2TP tunnels will be created when the connection is established between the L2TP access concentrator and the L2TP network server. So, to send over the Internet, a PPP link layer is activated and encapsulated. At this point, the end-user establishes a PPP connection with the ISP, and it will be active when the LAC accepts the connection.
To initiate the passage of link frames through the tunnel, there is a virtual PPP interface. Then, the job of the LNS is to receive the frames, remove their encapsulation, and further process them as regular frames.
L2TP combines with IPSec to secure the data payload. In addition, it can use up to 256-bit encryption keys and the 3DES algorithm when paired with IPSec. After pairing with IPSec, L2TP uses UDP ports 500+, 4500, and 1701. But before paring, it usually uses TCP port 1701.
The L2TP data packet structure includes the IP header, IPSec ESP header, UDP header, L2TP header, PPP header, PPP payload, IPSec ESP trailer, and IPSec authentication trailer.
What is L2TP used for?
L2TP is a very popular VPN protocol accessed by most VPN providers. You have read what L2TP is and how it works. Stay with us in this part of this guide to see what it’s used for and why you need L2TP.
Because IPSs use protocols to tunnel user data from their premises to a provider’s IP network, L2TP provides delivery services for ISPs. L2TP is also implemented as a configuration protocol to support VPN services Once you are a client of L2tP, you will be able to use it to connect to a remote LAN server because L2TP is capable of establishing tunnels. Therefore, L2TP is a good choice for connecting to remote local area networks to help access LANs from any location.
If you need to work with a VPN protocol that is reliable, stable, consistent, configurable, and protects against man-in-the-middle attacks, L2TP is what you want. If you buy a Mikrotik VPS, you can set up an L2TP VPN server on it and use all the mentioned features.
L2TP Passthrough
L2TP connections usually require accessing the web through a router. So, its traffic has to go through the router for the connection to work. To enable or disable L2TP traffic on L2TP passthrough, you need it as a router feature Although Nat does not work well with L2TP, enabling L2TP passthrough on your router, allows L2TP to solve this problem.
Advantages of L2TP
L2TP works across multiple platforms and supports Windows and macOS OSes and devices. It is preinstalled on these systems. Here are some of the most important features of L2TP A manual or automatic connection setting requires only a few simple steps.
Security
L2TP is one of the safest VPN protocols available. Using L2TP helps you protect data from being modified while it is being transferred between sender and receiver. Thus, L2TP encrypts the authentication process to make it more difficult for someone to tamper with it. L2TP works with AES and 3DES encryption algorithms to provide a secure connection.
If you care more about security than speed when choosing a VPN, L2TP is a good option for you because UDP encapsulating data is easier and faster to set up with most firewalls.
Speed
L2TP/IPSec is able to provide a regular non-encrypted connection speed to the server. But it depends on server configuration. For example, it can deliver 100 Mbps broadband or come close.
Reliable
Using UDP port 1701, port 500, & port 4500, L2TP provides a reliable link establishment.
Customizable
L2TP is flexible, lightweight, and adaptable to different encryption protocols.
Compatible
You don’t need to invest in expensive hardware to support an L2TP deployment in your network. L2TP is widely supported across platforms. Mobile devices, Linux, or BSD platforms could easily be your target.
Pairing up L2TP with IPSec
As you know, L2TP comes without any authentication or encryption. However, IPsec is a very flexible tunneling protocol for end-to-end security. Therefore, this lack is the reason why IPSec was added to L2TP to help provide encryption of user and control packets between L2TP tunnels. L2TP employs IPSec for additional security.
Disadvantages of L2TP
NAT firewalls do not block L2TP traffic, requiring L2TP passthrough Therefore, pay attention to setting L2TP properly so that NAT firewall does not block easily. Let’s examine what are the most annoying disadvantages of L2TP.
Security
The reason L2TP is always associated with IPSec is that L2TP encryption doesn’t actually exist in it. So, it’s not recommended to use only L2TP protocol when you are online. Although L2TP/IPSec is a secure VPN protocol, if you have very sensitive data, it is better to use a more secure protocol. Also, make sure that you use a reliable and no-logs VPN provider.
Speed
You can get faster speeds with L2TP, but you need to know that it is insecure by itself because that speed has no way of encryption or authentication. It is also slower than IPSec IKEv2 due to its double encapsulation.
Compromise
Due to leaks, the NSA and FBI are said to have weakened or cracked this protocol with backdoors, side-channel keys, or zero-day exploits. So, you have to consider that L2TP may be compromised.
Reliability
L2TP is not reliable as a means of circumventing network restrictions because it struggles to bypass firewalls.
A review of L2TP alternatives
Let’s explore the strengths and weaknesses of the L2TP VPN protocol in comparison to other VPN protocols.
L2TP vs SSTP
VPN Protocol | Stability | Encryption |
|---|---|---|
| L2TP | × | × |
| SSTP |  | |
L2TP vs. PPTP
| VPN Protocol | Security | Performance speed |
|---|---|---|
| L2TP | | × |
| PPTP | × | |
L2TP vs. WireGuard
| VPN Protocol | Security | Speed |
|---|---|---|
| L2TP | × | × |
| WireGuard | | |
L2TP vs. IKEv2
| VPN Protocol | Security | Stability and Reliability |
|---|---|---|
| L2TP | × | × |
| IKEv2 | | |
L2TP vs. SoftEther
| VPN Protocol | Speed | Stability | Accessibility and compatibility |
|---|---|---|---|
| L2TP | × | × | × |
| SoftEther | | | |
How to set up L2TP?
Setting up the L2TP VPN protocol is really easy. If you’re using it on a Windows or macOS device, you just need to go to your network settings and go through a few steps to set up and configure the L2TP connection. And when using L2TP/IPSec VPN protocol, you need to change a few options to select IPSec encryption.
But if you want to set it up on a device that doesn’t support L2TP and L2TP/IPSec, you have to do it manually. There are some additional steps that you must follow, but they should not be time-consuming or require advanced knowledge.
Conclusion
In this article, you learned about the L2TP VPN protocol and reviewed what it is used for. Now, you know how it works and what are the advantages and disadvantages of the L2TP VPN protocol. Important options for security, speed, and compromise are discussed to help you consider your priorities and needs in choosing a VPN. Windows and Mac operating systems offer support for L2TP. Thus, it is a widely accessible VPN protocol offered by various VPN services.
If you have used the L2TP VPN protocol or if you have recently migrated to one of its alternatives, share your experience with us.
