Packet-Loss Resiliency for Router Solicitations
RFC 7559
| Document | Type |
RFC - Proposed Standard
(May 2015; No errata)
Updates RFC 4861
|
|
|---|---|---|---|
| Last updated | 2015-10-14 | ||
| Replaces | draft-krishnan-6man-resilient-rs | ||
| Stream | IETF | ||
| Formats | plain text html pdf htmlized bibtex | ||
| Reviews | |||
| Stream | WG state | Submitted to IESG for Publication | |
| Document shepherd | Ole Trøan | ||
| Shepherd write-up | Show (last changed 2015-03-25) | ||
| IESG | IESG state | RFC 7559 (Proposed Standard) | |
| Consensus Boilerplate | Yes | ||
| Telechat date | |||
| Responsible AD | Brian Haberman | ||
| Send notices to | (None) | ||
| IANA | IANA review state | Version Changed - Review Needed | |
| IANA action state | No IANA Actions | ||
Internet Engineering Task Force (IETF) S. Krishnan
Request for Comments: 7559 Ericsson
Updates: 4861 D. Anipko
Category: Standards Track Unaffiliated
ISSN: 2070-1721 D. Thaler
Microsoft
May 2015
Packet-Loss Resiliency for Router Solicitations
Abstract
When an interface on a host is initialized, the host transmits Router
Solicitations in order to minimize the amount of time it needs to
wait until the next unsolicited multicast Router Advertisement is
received. In certain scenarios, these Router Solicitations
transmitted by the host might be lost. This document specifies a
mechanism for hosts to cope with the loss of the initial Router
Solicitations.
Status of This Memo
This is an Internet Standards Track document.
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
Internet Standards is available in Section 2 of RFC 5741.
Information about the current status of this document, any errata,
and how to provide feedback on it may be obtained at
http://www.rfc-editor.org/info/rfc7559.
Krishnan, et al. Standards Track [Page 1]
RFC 7559 Resilient RS Retransmission May 2015
Copyright Notice
Copyright (c) 2015 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
(http://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
1.1. Conventions Used in This Document . . . . . . . . . . . . 3
2. Proposed Algorithm . . . . . . . . . . . . . . . . . . . . . 3
2.1. Stopping the Retransmissions . . . . . . . . . . . . . . 3
3. Configuring the Use of Retransmissions . . . . . . . . . . . 4
4. Known Limitations . . . . . . . . . . . . . . . . . . . . . . 4
5. Security Considerations . . . . . . . . . . . . . . . . . . . 4
6. References . . . . . . . . . . . . . . . . . . . . . . . . . 5
6.1. Normative References . . . . . . . . . . . . . . . . . . 5
6.2. Informative References . . . . . . . . . . . . . . . . . 5
Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . 5
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 6
1. Introduction
As specified in [RFC4861], when an interface on a host is
initialized, in order to obtain Router Advertisements quickly, a host
transmits up to MAX_RTR_SOLICITATIONS (3) Router Solicitation (RS)
messages, each separated by at least RTR_SOLICITATION_INTERVAL (4)
seconds. In certain scenarios, these Router Solicitations
transmitted by the host might be lost. For example, the host is
connected to a bridged residential gateway over Ethernet or Wi-Fi.
LAN connectivity is achieved at interface initialization, but the
upstream WAN connectivity is not active yet. In this case, the host
just gives up after the initial RS retransmits.
Once the initial RSs are lost, the host gives up and assumes that
there are no routers on the link as specified in Section 6.3.7 of
[RFC4861]. The host will not have any form of Internet connectivity
until the next unsolicited multicast Router Advertisement is
received. These Router Advertisements are transmitted at most
Krishnan, et al. Standards Track [Page 2]
RFC 7559 Resilient RS Retransmission May 2015
MaxRtrAdvInterval seconds apart (maximum value 1800 seconds). Thus,
in the worst-case scenario a host would be without any connectivity
for 30 minutes. This delay may be unacceptable in some scenarios.
1.1. Conventions Used in This Document
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in [RFC2119].
2. Proposed Algorithm
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