Commentary on Inter-Domain Routing in the Internet
RFC 3221
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RFC - Informational
(December 2001; No errata)
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2013-03-02
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IAB
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plain text
pdf
html
bibtex
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(None)
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Consensus Boilerplate |
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Unknown
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RFC Editor Note |
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(None)
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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 [Page 1]
RFC 3221 Commentary on Inter-Domain Routing December 2001
1. Introduction
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.
These impacts include the potential for exhaustion of the existing
Autonomous System number space, increasing convergence times for
selection of stable alternate paths following withdrawal of route
announcements, the stability of table entries, and the average prefix
length of entries in the BGP table. The larger long term issue is
that of an increasingly denser inter-connectivity mesh between ASes,
causing a finer degree of granularity of inter-domain policy and
finer levels of control to undertake inter-domain traffic
engineering.
Various approaches to a refinement of the inter-domain routing
protocol and associated operating practices that may provide superior
scaling properties are identified as an area for further
investigation.
This document is the outcome of a collaborative exercise on the part
of the Internet Architecture Board.
2. Network Scaling and Inter-Domain Routing
Are there inherent scaling limitations in the technology of the
Internet or its architecture of deployment that may impact on the
ability of the Internet to meet escalating levels of demand? There
are a number of potential areas to search for such limitations.
These include the capacity of transmission systems, packet switching
capacity, the continued availability of protocol addresses, and the
capability of the routing system to produce a stable view of the
overall topology of the network. In this study we will look at this
latter capability with the objective of identifying some aspects of
the scaling properties of the Internet's routing system.
The basic structure of the Internet is a collection of networks, or
Autonomous Systems (ASes) that are interconnected to form a connected
domain. Each AS uses an interior routing system to maintain a
coherent view of the topology within the AS, and uses an exterior
routing system to maintain adjacency information with neighboring
ASes to create a view of the connectivity of the entire system.
Huston Informational [Page 2]
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