L2TP (Layer 2 Tunneling Protocol) and EoIP (Ethernet over IP) are two technologies used to create network tunnels, allowing traffic from one network to be encapsulated and transmitted over another network. Although both technologies can be used to connect geographically separated network segments, they have key differences in their design, uses and compatibility. Here I explain the main differences:

L2TP (Layer 2 Tunneling Protocol)

• Standard and Compatibility: L2TP is a Layer 2 tunneling protocol that has been standardized in RFC 2661 and is widely supported by a variety of devices and operating systems. L2TP is commonly used in combination with IPsec (as L2TP/IPsec) to provide security for traffic passing through the tunnel.
• Use: L2TP is widely used for VPNs (Virtual Private Networks), allowing users to securely connect to a corporate or home network over the Internet. The combination of L2TP with IPsec provides encryption and authentication, ensuring data privacy and security.
• Flexibility: Although L2TP is primarily a Layer 2 tunneling protocol, its broad compatibility and support for encryption make it suitable for a variety of usage scenarios, from secure remote access to branch office connectivity.

EoIP (Ethernet over IP)

• MikroTik Specific: EoIP is a proprietary MikroTik protocol designed to create Ethernet tunnels over IP connections. Unlike L2TP, EoIP is not a standard and therefore support is limited primarily to MikroTik devices.
• Use: EoIP is used to connect LAN (Local Area Network) segments over an IP network, such as the Internet, so that they appear to be on the same broadcast network. This is useful for situations where you need to extend the LAN over long distances, such as connecting multiple company headquarters.
• Security: EoIP by itself does not provide encryption, which means that for traffic security, it is usually used in conjunction with IPsec or encapsulated within another secure tunnel such as L2TP/IPsec or SSTP.

Comparison and Considerations

• Standards and Compatibility: L2TP is a standard supported by many manufacturers and devices, making it a flexible option for creating VPNs. EoIP is specific to MikroTik, limiting its use to environments where all devices involved are MikroTik.
• Purpose and Application: L2TP is commonly chosen for secure remote access VPNs, while EoIP is used to extend LAN networks over IP, particularly in MikroTik implementations.
• Security: L2TP, especially in combination with IPsec, provides strong security features. EoIP requires additional measures to encrypt traffic, such as the use of IPsec.

In summary, the choice between L2TP and EoIP will depend on the specific requirements of the project, including the need for open standards and compatibility with non-MikroTik devices, as well as security considerations and the purpose of the tunnel.