draft-ietf-grow-va-03.txt   draft-ietf-grow-va-04.txt 
Network Working Group P. Francis Network Working Group P. Francis
Internet-Draft MPI-SWS Internet-Draft MPI-SWS
Intended status: Informational X. Xu Intended status: Informational X. Xu
Expires: March 4, 2011 Huawei Expires: August 26, 2011 Huawei
H. Ballani H. Ballani
Cornell U. Cornell U.
D. Jen D. Jen
UCLA UCLA
R. Raszuk R. Raszuk
Cisco Cisco
L. Zhang L. Zhang
UCLA UCLA
August 31, 2010 February 22, 2011
FIB Suppression with Virtual Aggregation FIB Suppression with Virtual Aggregation
draft-ietf-grow-va-03.txt draft-ietf-grow-va-04.txt
Abstract Abstract
The continued growth in the Default Free Routing Table (DFRT) The continued growth in the Default Free Routing Table (DFRT)
stresses the global routing system in a number of ways. One of the stresses the global routing system in a number of ways. One of the
most costly stresses is FIB size: ISPs often must upgrade router most costly stresses is FIB size: ISPs often must upgrade router
hardware simply because the FIB has run out of space, and router hardware simply because the FIB has run out of space, and router
vendors must design routers that have adequate FIB. FIB suppression vendors must design routers that have adequate FIB. FIB suppression
is an approach to relieving stress on the FIB by NOT loading selected is an approach to relieving stress on the FIB by NOT loading selected
RIB entries into the FIB. Virtual Aggregation (VA) allows ISPs to RIB entries into the FIB. Virtual Aggregation (VA) allows ISPs to
shrink the FIBs of any and all routers, easily by an order of shrink the FIBs of any and all routers, easily by an order of
magnitude with negligible increase in path length and load. FIB magnitude with negligible increase in path length and load. FIB
suppression deployed autonomously by an ISP (cooperation between ISPs suppression deployed autonomously by an ISP (cooperation between ISPs
is not required), and can co-exist with legacy routers in the ISP. is not required), and can co-exist with legacy routers in the ISP.
There are no changes from the 03 version.
Status of this Memo Status of this Memo
This Internet-Draft is submitted to IETF in full conformance with the This Internet-Draft is submitted to IETF in full conformance with the
provisions of BCP 78 and BCP 79. provisions of BCP 78 and BCP 79.
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This Internet-Draft will expire on August 26, 2011.
This Internet-Draft will expire on March 4, 2011.
Copyright Notice Copyright Notice
Copyright (c) 2010 IETF Trust and the persons identified as the Copyright (c) 2011 IETF Trust and the persons identified as the
document authors. All rights reserved. document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal This document is subject to BCP 78 and the IETF Trust's Legal
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described in the Simplified BSD License. described in the Simplified BSD License.
Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 4
1.1. Scope of this Document . . . . . . . . . . . . . . . . . . 4 1.1. Scope of this Document . . . . . . . . . . . . . . . . . . 5
1.2. Requirements notation . . . . . . . . . . . . . . . . . . 5 1.2. Requirements notation . . . . . . . . . . . . . . . . . . 6
1.3. Terminology . . . . . . . . . . . . . . . . . . . . . . . 5 1.3. Terminology . . . . . . . . . . . . . . . . . . . . . . . 6
2. Overview of Virtual Aggregation (VA) . . . . . . . . . . . . . 6 2. Overview of Virtual Aggregation (VA) . . . . . . . . . . . . . 7
2.1. Mix of legacy and VA routers . . . . . . . . . . . . . . . 8 2.1. Mix of legacy and VA routers . . . . . . . . . . . . . . . 9
2.2. Summary of Tunnels and Paths . . . . . . . . . . . . . . . 9 2.2. Summary of Tunnels and Paths . . . . . . . . . . . . . . . 10
3. Specification of VA . . . . . . . . . . . . . . . . . . . . . 10 3. Specification of VA . . . . . . . . . . . . . . . . . . . . . 11
3.1. VA Operation . . . . . . . . . . . . . . . . . . . . . . . 11 3.1. VA Operation . . . . . . . . . . . . . . . . . . . . . . . 12
3.1.1. Legacy Routers . . . . . . . . . . . . . . . . . . . . 11 3.1.1. Legacy Routers . . . . . . . . . . . . . . . . . . . . 12
3.1.2. Advertising and Handling Virtual Prefixes (VP) . . . . 11 3.1.2. Advertising and Handling Virtual Prefixes (VP) . . . . 12
3.1.3. Border VA Routers . . . . . . . . . . . . . . . . . . 15 3.1.3. Border VA Routers . . . . . . . . . . . . . . . . . . 16
3.1.4. Advertising and Handling Sub-Prefixes . . . . . . . . 15 3.1.4. Advertising and Handling Sub-Prefixes . . . . . . . . 16
3.1.5. Suppressing FIB Sub-prefix Routes . . . . . . . . . . 16 3.1.5. Suppressing FIB Sub-prefix Routes . . . . . . . . . . 17
3.2. New Configuration . . . . . . . . . . . . . . . . . . . . 17 3.2. New Configuration . . . . . . . . . . . . . . . . . . . . 18
4. Usage of Tunnels . . . . . . . . . . . . . . . . . . . . . . . 18 4. Usage of Tunnels . . . . . . . . . . . . . . . . . . . . . . . 19
4.1. MPLS tunnels . . . . . . . . . . . . . . . . . . . . . . . 18 4.1. MPLS tunnels . . . . . . . . . . . . . . . . . . . . . . . 19
4.2. Usage of Inner Label . . . . . . . . . . . . . . . . . . . 19 4.2. Usage of Inner Label . . . . . . . . . . . . . . . . . . . 20
5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 19 5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 20
6. Security Considerations . . . . . . . . . . . . . . . . . . . 19 6. Security Considerations . . . . . . . . . . . . . . . . . . . 20
6.1. Properly Configured VA . . . . . . . . . . . . . . . . . . 19 6.1. Properly Configured VA . . . . . . . . . . . . . . . . . . 20
6.2. Mis-configured VA . . . . . . . . . . . . . . . . . . . . 20 6.2. Mis-configured VA . . . . . . . . . . . . . . . . . . . . 21
7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 20 7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 21
8. References . . . . . . . . . . . . . . . . . . . . . . . . . . 21 8. References . . . . . . . . . . . . . . . . . . . . . . . . . . 22
8.1. Normative References . . . . . . . . . . . . . . . . . . . 21 8.1. Normative References . . . . . . . . . . . . . . . . . . . 22
8.2. Informative References . . . . . . . . . . . . . . . . . . 21 8.2. Informative References . . . . . . . . . . . . . . . . . . 22
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 22 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 23
1. Introduction 1. Introduction
ISPs today manage constant DFRT growth in a number of ways. One way, ISPs today manage constant DFRT growth in a number of ways. One way,
of course, is for ISPs to upgrade their router hardware before DFRT of course, is for ISPs to upgrade their router hardware before DFRT
growth outstrips the size of the FIB. This is too expensive for many growth outstrips the size of the FIB. This is too expensive for many
ISPs. They would prefer to extend the lifetime of routers whose FIBs ISPs. They would prefer to extend the lifetime of routers whose FIBs
can no longer hold the full DFRT. can no longer hold the full DFRT.
A common approach taken by lower-tier ISPs is to default route to A common approach taken by lower-tier ISPs is to default route to
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