Enterprise Multihoming using Provider-Assigned IPv6 Addresses without Network Prefix Translation: Requirements and Solutions
RFC 8678
Document | Type | RFC - Informational (December 2019; No errata) | |
---|---|---|---|
Authors | Fred Baker , Chris Bowers , Jen Linkova | ||
Last updated | 2019-12-18 | ||
Replaces | draft-bowbakova-rtgwg-enterprise-pa-multihoming | ||
Stream | Internent Engineering Task Force (IETF) | ||
Formats | plain text html xml pdf htmlized (tools) htmlized bibtex | ||
Reviews | |||
Stream | WG state | Submitted to IESG for Publication | |
Document shepherd | Ron Bonica | ||
Shepherd write-up | Show (last changed 2018-05-11) | ||
IESG | IESG state | RFC 8678 (Informational) | |
Action Holders |
(None)
|
||
Consensus Boilerplate | Yes | ||
Telechat date | |||
Responsible AD | Martin Vigoureux | ||
Send notices to | Ron Bonica <rbonica@juniper.net> | ||
IANA | IANA review state | Version Changed - Review Needed | |
IANA action state | No IANA Actions |
Internet Engineering Task Force (IETF) F. Baker Request for Comments: 8678 Category: Informational C. Bowers ISSN: 2070-1721 Juniper Networks J. Linkova Google December 2019 Enterprise Multihoming Using Provider-Assigned IPv6 Addresses without Network Prefix Translation: Requirements and Solutions Abstract Connecting an enterprise site to multiple ISPs over IPv6 using provider-assigned addresses is difficult without the use of some form of Network Address Translation (NAT). Much has been written on this topic over the last 10 to 15 years, but it still remains a problem without a clearly defined or widely implemented solution. Any multihoming solution without NAT requires hosts at the site to have addresses from each ISP and to select the egress ISP by selecting a source address for outgoing packets. It also requires routers at the site to take into account those source addresses when forwarding packets out towards the ISPs. This document examines currently available mechanisms for providing a solution to this problem for a broad range of enterprise topologies. It covers the behavior of routers to forward traffic by taking into account source address, and it covers the behavior of hosts to select appropriate default source addresses. It also covers any possible role that routers might play in providing information to hosts to help them select appropriate source addresses. In the process of exploring potential solutions, this document also makes explicit requirements for how the solution would be expected to behave from the perspective of an enterprise site network administrator. Status of This Memo This document is not an Internet Standards Track specification; it is published for informational purposes. This document is a product of the Internet Engineering Task Force (IETF). It represents the consensus of the IETF community. It has received public review and has been approved for publication by the Internet Engineering Steering Group (IESG). Not all documents approved by the IESG are candidates for any level of Internet Standard; see Section 2 of RFC 7841. Information about the current status of this document, any errata, and how to provide feedback on it may be obtained at https://www.rfc-editor.org/info/rfc8678. Copyright Notice Copyright (c) 2019 IETF Trust and the persons identified as the document authors. All rights reserved. This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (https://trustee.ietf.org/license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License. Table of Contents 1. Introduction 2. Requirements Language 3. Terminology 4. Enterprise Multihoming Use Cases 4.1. Simple ISP Connectivity with Connected SERs 4.2. Simple ISP Connectivity Where SERs Are Not Directly Connected 4.3. Enterprise Network Operator Expectations 4.4. More Complex ISP Connectivity 4.5. ISPs and Provider-Assigned Prefixes 4.6. Simplified Topologies 5. Generating Source-Prefix-Scoped Forwarding Tables 6. Mechanisms for Hosts To Choose Good Default Source Addresses in a Multihomed Site 6.1. Default Source Address Selection Algorithm on Hosts 6.2. Selecting Default Source Address When Both Uplinks Are Working 6.2.1. Distributing Default Address Selection Policy Table with DHCPv6 6.2.2. Controlling Default Source Address Selection with Router Advertisements 6.2.3. Controlling Default Source Address Selection with ICMPv6 6.2.4. Summary of Methods for Controlling Default Source Address Selection to Implement Routing Policy 6.3. Selecting Default Source Address When One Uplink Has Failed 6.3.1. Controlling Default Source Address Selection with DHCPv6 6.3.2. Controlling Default Source Address Selection with Router Advertisements 6.3.3. Controlling Default Source Address Selection with ICMPv6 6.3.4. Summary of Methods for Controlling Default Source Address Selection on the Failure of an UplinkShow full document text