Report from the IAB Workshop on Routing and Addressing
RFC 4984

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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