Network Working Group G. Huston Request for Comments: 3221 Internet Architecture Board Category: Informational December 2001 Commentary on Inter-Domain Routing in the Internet Status of this Memo This memo provides information for the Internet community. It does not specify an Internet standard of any kind. Distribution of this memo is unlimited. Copyright Notice Copyright (C) The Internet Society (2001). All Rights Reserved. Abstract This document examines the various longer term trends visible within the characteristics of the Internet's BGP table and identifies a number of operational practices and protocol factors that contribute to these trends. The potential impacts of these practices and protocol properties on the scaling properties of the inter-domain routing space are examined. This document is the outcome of a collaborative exercise on the part of the Internet Architecture Board. Table of Contents 1. Introduction................................................. 2 2. Network Scaling and Inter-Domain Routing ................... 2 3. Measurements of the total size of the BGP Table ............ 4 4. Related Measurements derived from BGP Table ................ 7 5. Current State of inter-AS routing in the Internet .......... 11 6. Future Requirements for the Exterior Routing System ........ 14 7. Architectural Approaches to a scalable Exterior Routing Protocol........................................... 15 8. Directions for Further Activity ............................ 21 9. Security Considerations .................................... 22 10. References ................................................. 23 11. Acknowledgements ........................................... 24 12. Author's Address ........................................... 24 13. Full Copyright Statement ................................... 25 Huston Informational