Reaction of Stateless Address Autoconfiguration (SLAAC) to Flash- Renumbering Events
draft-ietf-v6ops-slaac-renum-05
Document | Type | Active Internet-Draft (v6ops WG) | ||
---|---|---|---|---|
Authors | Fernando Gont , Jan Zorz , Richard Patterson | |||
Last updated | 2021-01-11 (latest revision 2020-11-02) | |||
Replaces | draft-gont-v6ops-slaac-renum | |||
Stream | IETF | |||
Intended RFC status | Informational | |||
Formats | plain text pdf htmlized (tools) htmlized bibtex | |||
Reviews | ||||
Stream | WG state | Submitted to IESG for Publication | ||
Document shepherd | Owen DeLong | |||
Shepherd write-up | Show (last changed 2020-07-07) | |||
IESG | IESG state | RFC Ed Queue | ||
Action Holders |
(None)
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Consensus Boilerplate | Yes | |||
Telechat date | ||||
Responsible AD | Warren Kumari | |||
Send notices to | Owen DeLong <owen@delong.com>, v6ops@ietf.org | |||
IANA | IANA review state | Version Changed - Review Needed | ||
IANA action state | No IANA Actions | |||
RFC Editor | RFC Editor state | AUTH48 | ||
Details |
IPv6 Operations Working Group (v6ops) F. Gont Internet-Draft SI6 Networks Intended status: Informational J. Zorz Expires: May 6, 2021 6connect R. Patterson Sky UK November 2, 2020 Reaction of Stateless Address Autoconfiguration (SLAAC) to Flash- Renumbering Events draft-ietf-v6ops-slaac-renum-05 Abstract In scenarios where network configuration information related to IPv6 prefixes becomes invalid without any explicit and reliable signaling of that condition (such as when a Customer Edge router crashes and reboots without knowledge of the previously-employed prefixes), nodes on the local network may continue using stale prefixes for an unacceptably long time (on the order of several days), thus resulting in connectivity problems. This document describes this issue and discusses operational workarounds that may help to improve network robustness. Additionally, it highlights areas where further work may be needed. Status of This Memo This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet- Drafts is at https://datatracker.ietf.org/drafts/current/. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." This Internet-Draft will expire on May 6, 2021. Copyright Notice Copyright (c) 2020 IETF Trust and the persons identified as the document authors. All rights reserved. Gont, et al. Expires May 6, 2021 [Page 1] Internet-Draft Reaction to Renumbering Events November 2020 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 2. Analysis of the Problem . . . . . . . . . . . . . . . . . . . 5 2.1. Use of Dynamic Prefixes . . . . . . . . . . . . . . . . . 5 2.2. Default Timer Values in IPv6 Stateless Address Autoconfiguration (SLAAC) . . . . . . . . . . . . . . . . 6 2.3. Recovering from Stale Network Configuration Information . 7 2.4. Lack of Explicit Signaling about Stale Information . . . 7 2.5. Interaction Between DHCPv6-PD and SLAAC . . . . . . . . . 8 3. Operational Mitigations . . . . . . . . . . . . . . . . . . . 8 3.1. Stable Prefixes . . . . . . . . . . . . . . . . . . . . . 8 3.2. SLAAC Parameter Tweaking . . . . . . . . . . . . . . . . 8 4. Future Work . . . . . . . . . . . . . . . . . . . . . . . . . 9 5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 10 6. Security Considerations . . . . . . . . . . . . . . . . . . . 10 7. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 10 8. References . . . . . . . . . . . . . . . . . . . . . . . . . 11 8.1. Normative References . . . . . . . . . . . . . . . . . . 11 8.2. Informative References . . . . . . . . . . . . . . . . . 11 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 13 1. Introduction IPv6 Stateless address autoconfiguration (SLAAC) [RFC4862] conveys information about prefixes to be employed for address configuration via Prefix Information Options (PIOs) sent in Router Advertisement (RA) messages. IPv6 largely assumes prefix stability, with network renumbering only taking place in a planned manner, with old/stale prefixes being phased-out via reduced prefix lifetimes, and new prefixes (with longer lifetimes) being introduced at the same time. However, there are several scenarios that may lead to the so-called "flash-renumbering" events, where the prefix employed by a network suddenly becomes invalid and replaced by a new prefix. In some ofShow full document text