Operation of Anycast Services
RFC 4786
| Document | Type |
RFC - Best Current Practice
(December 2006; No errata)
Also known as BCP 126
|
|
|---|---|---|---|
| Last updated | 2015-10-14 | ||
| Stream | IETF | ||
| Formats | plain text pdf html bibtex | ||
| Stream | WG state | (None) | |
| Document shepherd | No shepherd assigned | ||
| IESG | IESG state | RFC 4786 (Best Current Practice) | |
| Consensus Boilerplate | Unknown | ||
| Telechat date | |||
| Responsible AD | David Kessens | ||
| Send notices to | gih@telstra.net | ||
Network Working Group J. Abley
Request for Comments: 4786 Afilias Canada
BCP: 126 K. Lindqvist
Category: Best Current Practice Netnod Internet Exchange
December 2006
Operation of Anycast Services
Status of This Memo
This document specifies an Internet Best Current Practices for the
Internet Community, and requests discussion and suggestions for
improvements. Distribution of this memo is unlimited.
Copyright Notice
Copyright (C) The IETF Trust (2006).
Abstract
As the Internet has grown, and as systems and networked services
within enterprises have become more pervasive, many services with
high availability requirements have emerged. These requirements have
increased the demands on the reliability of the infrastructure on
which those services rely.
Various techniques have been employed to increase the availability of
services deployed on the Internet. This document presents commentary
and recommendations for distribution of services using anycast.
Abley & Lindqvist Best Current Practice [Page 1]
RFC 4786 Anycast BCP December 2006
Table of Contents
1. Introduction ....................................................3
2. Terminology .....................................................4
3. Anycast Service Distribution ....................................5
3.1. General Description ........................................5
3.2. Goals ......................................................5
4. Design ..........................................................6
4.1. Protocol Suitability .......................................6
4.2. Node Placement .............................................7
4.3. Routing Systems ............................................8
4.3.1. Anycast within an IGP ...............................8
4.3.2. Anycast within the Global Internet ..................9
4.4. Routing Considerations .....................................9
4.4.1. Signalling Service Availability .....................9
4.4.2. Covering Prefix ....................................10
4.4.3. Equal-Cost Paths ...................................10
4.4.4. Route Dampening ....................................12
4.4.5. Reverse Path Forwarding Checks .....................13
4.4.6. Propagation Scope ..................................13
4.4.7. Other Peoples' Networks ............................14
4.4.8. Aggregation Risks ..................................14
4.5. Addressing Considerations .................................15
4.6. Data Synchronisation ......................................15
4.7. Node Autonomy .............................................16
4.8. Multi-Service Nodes .......................................17
4.8.1. Multiple Covering Prefixes .........................17
4.8.2. Pessimistic Withdrawal .............................17
4.8.3. Intra-Node Interior Connectivity ...................18
4.9. Node Identification by Clients ............................18
5. Service Management .............................................19
5.1. Monitoring ................................................19
6. Security Considerations ........................................19
6.1. Denial-of-Service Attack Mitigation .......................19
6.2. Service Compromise ........................................20
6.3. Service Hijacking .........................................20
7. Acknowledgements ...............................................21
8. References .....................................................21
8.1. Normative References ......................................21
8.2. Informative References ....................................21
Abley & Lindqvist Best Current Practice [Page 2]
RFC 4786 Anycast BCP December 2006
1. Introduction
This document is addressed to network operators who are considering
whether to deploy or operate a distributed service using anycast. It
describes the best current practice for doing so, but does not
recommend whether any particular service should or should not be
deployed using anycast.
To distribute a service using anycast, the service is first
associated with a stable set of IP addresses, and reachability to
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