Certain routing protocols are common in the Internet, but the authors of this document cannot in good conscience recommend their use. This is not because they do not work correctly, but because the characteristics of the Internet assumed in their design (simple routing, no policy, a single "core router" network under common administration, limited complexity, or limited network diameter) are not attributes of today's Internet. Those parts of the Internet that still use them are generally limited "fringe" domains with limited complexity.
As a matter of good faith, collected wisdom concerning their implementation is recorded in this section.