As covered in Chapter 7, “Kernel Support Tools”, adding additional functions to Internet gateways can add additional value to a Linux router and, indeed, often gives Linux an edge over traditional routers as Internet access gateways.
There are additional considerations, or special cases, that also arise when planning and deploying networks that you should be aware of.
Chapter 4, “IPv4 and IPv6 Addressing,” covers the innards of addressing networks. Organizations choosing to support IPv6 will need phase-in methodologies to support both versions of the Internet protocol.
RFC 1933, “Transition Mechanisms for IPv6 Hosts and Routers,” defines two methods for transitioning to IPv6: dual IP layer ...