Ethernet over IP (EoIP)

Ethernet over IP (often abbreviated as "EoIP" or sometimes "EthoIP") refers to the encapsulation of Ethernet frames within IP packets. This allows Ethernet traffic to be transported over an IP network, and it can be used to connect remote Ethernet networks over the public Internet or private IP networks.

One of the most common uses of Ethernet over IP is in creating Layer 2 (Ethernet) tunnels between remote locations. By encapsulating Ethernet frames within IP packets, these frames can be transported across IP-based networks that do not inherently support Ethernet frame forwarding, such as the public Internet.

Some key points about Ethernet over IP include:

  1. Tunneling Mechanism: EoIP provides a method for creating a Layer 2 tunnel, effectively bridging two Ethernet segments over an IP network.
  2. Interoperability: EoIP can be used to connect Ethernet networks across various types of infrastructure, whether they be wired, wireless, or even satellite connections.
  3. Security Considerations: EoIP by itself does not provide encryption. If security is a concern, you would typically combine EOIP with another tunneling protocol that does provide encryption, such as IPsec.
  4. Performance: Encapsulating Ethernet in IP adds overhead to each packet. It's essential to consider this overhead, especially when dealing with bandwidth-sensitive applications or when the available bandwidth is limited.

As a technology, Cisco devices don't have a particular implementation called EoIP, however, they achieve this operation using technologies such as L2TPv3, GRE tunnels, and VXLAN to achieve Ethernet over IP. Mikrotik has an EoIP implementation that is natively supported by their devices.

So Ethernet over IP provides a way to bridge remote Ethernet networks across IP-based networks. Like all tunneling technologies, it adds some overhead, and security considerations must be taken into account when deploying it.