Publication date : September 2002
RFC Author(s) : R.Housley, S.Hollenbeck
Category : informational
EtherIP protocol developed in 1991, and used to tunnel Ethernet and IEEE 802.3 media access control (MAC) frames (including IEEE 802.1Q [VLAN] datagrams) across an IP internet.
The EtherIP datagrams contains 16-bit header and a variable-length encapsulated Ethernet or IEEE 802.3 frame that immediately follows IP fields.
The 16-bit of EtherIP header contains two fields, the version 4-bit that must be set to 3 (0011) and 12-bit reserved reserved for future that have to be set to zero, for encapsulation and decapsulation operations. An IP datagram with a EtherIP header must set the IPv4 protocol to 97 (decimal).
The brigde-like station must listen for IP datagram that contains the protocol 97 and ignore the rest LAN frames. if this case it extract MAC from datagrams on the LAN and calculate the (FCS) frame check sequence even the IP checksum does not provide integrity protection for Ethernet/IEEE 802.3, and append the frame as part of data link layer.
One security consideration solution is to protect the IP datagram that carry EtherIP with IPsec [RFC2401].