Filtering Routers in a Small Office/Home Office with a Mixed OS Environment

In this paper the author explores one layer of a multi-layered defense of the internal network of a SOHO user, and how to configure the packet filtering capability of a cable or digital subscriber line (DSL) router for a mixed OS network. With the filter set limitations of most cable/DSL routers, a normal network security filter set must be reevaluated to determine the most important services that must be blocked. A reevaluation must also be done in a mixed OS environment since a normal network security filter set for a homogeneous network will generally not be sufficiently for a different OS. This paper is an extension of the work of Rick Thompson [1] and Patrick Harris [2]