The requirements for routing architectures described in this document were produced by two sub-groups under the IRTF Routing Research Group (RRG) in 2001, with some editorial updates up to 2006. The two sub-groups worked independently, and the resulting requirements represent two separate views of the problem and of what is required to fix the problem. This document may usefully serve as part of the recommended reading for anyone who works on routing architecture designs for the Internet in the future.The document is published with the support of the IRTF RRG as a record of the work completed at that time, but with the understanding that it does not necessarily represent either the latest technical understanding or the technical consensus of the research group at the date of publication.