Donald Bren School of Information and Computer Sciences

This report describes a "low technology" method for connecting into the ARPA Internet. The use of a RawPacket interface in a system which supoprts IP makes possible the construction of a split-gateway between two hosts. The RawPacket interface permits a user-level process to introduce arbitrary packets into the IP layer, resulting in a virtual network interface. Since the split-gateway is implemented using a RawPacket interface, two networks may be connected together using a convenient medium which does not require explicit kernel support. Hence, split-gateways are well-suited for use as stub-gateways, connecting a local network to a long-haul network such as the ARPA backbone. In particular, the split-gateway discussed in this report achieves a reasonable level of connectivity for a comparatively small expenditure.

This report details how the RawPacket software and split-gateways are implemented. In addition, various daemon configurations are presented, modifications to the operating environment are discussed, and some performance measurements are given.