This tarball contains a new EtherIP driver which will provide a virtual ethernet interface instead of using gif in combination with a bridge.
This diff contains a port of some parts of the OpenBSD EtherIP code, which will allow one to bridge gif interfaces, making them send and receive RFC 3378 EtherIP packets.
This code is somewhat buggy, but it works for non-multicast, non-broadcast IPv4 over the bridged ethernet. NetBSD 3.0 contains this code.