Guidelines for Multihomed and IPv4/IPv6 Dual-Stack Interactive Connectivity Establishment (ICE)
RFC 8421
| Document | Type |
RFC - Best Current Practice
(July 2018; No errata)
Also known as BCP 217
|
|
|---|---|---|---|
| Last updated | 2018-07-19 | ||
| Replaces | draft-ietf-mmusic-ice-dualstack-fairness | ||
| Stream | IETF | ||
| Formats | plain text html pdf htmlized bibtex | ||
| Reviews | |||
| Stream | WG state | Submitted to IESG for Publication | |
| Document shepherd | Ari Keränen | ||
| Shepherd write-up | Show (last changed 2016-04-07) | ||
| IESG | IESG state | RFC 8421 (Best Current Practice) | |
| Consensus Boilerplate | Yes | ||
| Telechat date | |||
| Responsible AD | Ben Campbell | ||
| Send notices to | "Ari Keranen" <ari.keranen@ericsson.com> | ||
| IANA | IANA review state | IANA OK - No Actions Needed | |
| IANA action state | No IANA Actions | ||
Internet Engineering Task Force (IETF) P. Martinsen
Request for Comments: 8421 Cisco
BCP: 217 T. Reddy
Category: Best Current Practice McAfee, Inc.
ISSN: 2070-1721 P. Patil
Cisco
July 2018
Guidelines for Multihomed and IPv4/IPv6 Dual-Stack
Interactive Connectivity Establishment (ICE)
Abstract
This document provides guidelines on how to make Interactive
Connectivity Establishment (ICE) conclude faster in multihomed and
IPv4/IPv6 dual-stack scenarios where broken paths exist. The
provided guidelines are backward compatible with the original ICE
specification (see RFC 5245).
Status of This Memo
This memo documents an Internet Best Current Practice.
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). Further information on
BCPs is available in 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/rfc8421.
Copyright Notice
Copyright (c) 2018 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.
Martinsen, et al. Best Current Practice [Page 1]
RFC 8421 ICE Multihomed and Dual-Stack Guidelines July 2018
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Notational Conventions . . . . . . . . . . . . . . . . . . . 3
3. ICE Multihomed Recommendations . . . . . . . . . . . . . . . 3
4. ICE Dual-Stack Recommendations . . . . . . . . . . . . . . . 4
5. Compatibility . . . . . . . . . . . . . . . . . . . . . . . . 5
6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 7
7. Security Considerations . . . . . . . . . . . . . . . . . . . 7
8. References . . . . . . . . . . . . . . . . . . . . . . . . . 8
8.1. Normative References . . . . . . . . . . . . . . . . . . 8
8.2. Informative References . . . . . . . . . . . . . . . . . 8
Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . 8
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 9
1. Introduction
In multihomed and IPv4/IPv6 dual-stack environments, ICE [RFC8445]
would benefit by a fair distribution of its connectivity checks
across available interfaces or IP address types. With a fair
distribution of the connectivity checks, excessive delays are avoided
if a particular network path is broken or slow. Arguably, it would
be better to put the interfaces or address types known to the
application last in the checklist. However, the main motivation by
ICE is to make no assumptions regarding network topology; hence, a
fair distribution of the connectivity checks is more appropriate. If
an application operates in a well-known environment, it can safely
override the recommendation given in this document.
Applications should take special care to deprioritize network
interfaces known to provide unreliable connectivity when operating in
a multihomed environment. For example, certain tunnel services might
provide unreliable connectivity. Doing so will ensure a more fair
distribution of the connectivity checks across available network
interfaces on the device. The simple guidelines presented here
describe how to deprioritize interfaces known by the application to
provide unreliable connectivity.
There is also a need to introduce better handling of connectivity
checks for different IP address families in dual-stack IPv4/IPv6 ICE
scenarios. Following the recommendations from RFC 6724 [RFC6724]
will lead to prioritization of IPv6 over IPv4 for the same candidate
type. Due to this, connectivity checks for candidates of the same
type (host, reflexive, or relay) are sent such that an IP address
family is completely depleted before checks from the other address
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