Report from the IAB Workshop on Routing and Addressing
RFC 4984
Network Working Group D. Meyer, Ed.
Request for Comments: 4984 L. Zhang, Ed.
Category: Informational K. Fall, Ed.
September 2007
Report from the IAB Workshop on Routing and Addressing
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.
Abstract
This document reports the outcome of the Routing and Addressing
Workshop that was held by the Internet Architecture Board (IAB) on
October 18-19, 2006, in Amsterdam, Netherlands. The primary goal of
the workshop was to develop a shared understanding of the problems
that the large backbone operators are facing regarding the
scalability of today's Internet routing system. The key workshop
findings include an analysis of the major factors that are driving
routing table growth, constraints in router technology, and the
limitations of today's Internet addressing architecture. It is hoped
that these findings will serve as input to the IETF community and
help identify next steps towards effective solutions.
Note that this document is a report on the proceedings of the
workshop. The views and positions documented in this report are
those of the workshop participants and not of the IAB. Furthermore,
note that work on issues related to this workshop report is
continuing, and this document does not intend to reflect the
increased understanding of issues nor to discuss the range of
potential solutions that may be the outcome of this ongoing work.
Meyer, et al. Informational [Page 1]
RFC 4984 IAB Workshop on Routing & Addressing September 2007
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Key Findings from the Workshop . . . . . . . . . . . . . . . . 4
2.1. Problem #1: The Scalability of the Routing System . . . . 4
2.1.1. Implications of DFZ RIB Growth . . . . . . . . . . . . 5
2.1.2. Implications of DFZ FIB Growth . . . . . . . . . . . . 6
2.2. Problem #2: The Overloading of IP Address Semantics . . . 6
2.3. Other Concerns . . . . . . . . . . . . . . . . . . . . . . 7
2.4. How Urgent Are These Problems? . . . . . . . . . . . . . . 8
3. Current Stresses on the Routing and Addressing System . . . . 8
3.1. Major Factors Driving Routing Table Growth . . . . . . . . 8
3.1.1. Avoiding Renumbering . . . . . . . . . . . . . . . . . 9
3.1.2. Multihoming . . . . . . . . . . . . . . . . . . . . . 10
3.1.3. Traffic Engineering . . . . . . . . . . . . . . . . . 10
3.2. IPv6 and Its Potential Impact on Routing Table Size . . . 11
4. Implications of Moore's Law on the Scaling Problem . . . . . . 11
4.1. Moore's Law . . . . . . . . . . . . . . . . . . . . . . . 12
4.1.1. DRAM . . . . . . . . . . . . . . . . . . . . . . . . . 13
4.1.2. Off-chip SRAM . . . . . . . . . . . . . . . . . . . . 13
4.2. Forwarding Engines . . . . . . . . . . . . . . . . . . . . 13
4.3. Chip Costs . . . . . . . . . . . . . . . . . . . . . . . . 14
4.4. Heat and Power . . . . . . . . . . . . . . . . . . . . . . 14
4.5. Summary . . . . . . . . . . . . . . . . . . . . . . . . . 15
5. What Is on the Horizon . . . . . . . . . . . . . . . . . . . . 15
5.1. Continual Growth . . . . . . . . . . . . . . . . . . . . . 15
5.2. Large Numbers of Mobile Networks . . . . . . . . . . . . . 16
5.3. Orders of Magnitude Increase in Mobile Edge Devices . . . 16
6. What Approaches Have Been Investigated . . . . . . . . . . . . 17
6.1. Lessons from MULTI6 . . . . . . . . . . . . . . . . . . . 17
6.2. SHIM6: Pros and Cons . . . . . . . . . . . . . . . . . . . 18
6.3. GSE/Indirection Solutions: Costs and Benefits . . . . . . 19
6.4. Future for Indirection . . . . . . . . . . . . . . . . . . 20
7. Problem Statements . . . . . . . . . . . . . . . . . . . . . . 21
7.1. Problem #1: Routing Scalability . . . . . . . . . . . . . 21
7.2. Problem #2: The Overloading of IP Address Semantics . . . 22
7.2.1. Definition of Locator and Identifier . . . . . . . . . 22
7.2.2. Consequence of Locator and Identifier Overloading . . 23
7.2.3. Traffic Engineering and IP Address Semantics
Overload . . . . . . . . . . . . . . . . . . . . . . . 24
7.3. Additional Issues . . . . . . . . . . . . . . . . . . . . 24
7.3.1. Routing Convergence . . . . . . . . . . . . . . . . . 24
7.3.2. Misaligned Costs and Benefits . . . . . . . . . . . . 25
7.3.3. Other Concerns . . . . . . . . . . . . . . . . . . . . 25
Show full document text