Packet-Loss Resiliency for Router Solicitations
RFC 7559
Document | Type |
RFC - Proposed Standard
(May 2015; No errata)
Updates RFC 4861
|
|
---|---|---|---|
Authors | Suresh Krishnan , Dmitry Anipko , Dave Thaler | ||
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) | |
Action Holders |
(None)
|
||
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 AlgorithmShow full document text