draft-ietf-v6ops-cpe-slaac-renum-00.txt   draft-ietf-v6ops-cpe-slaac-renum-01.txt 
IPv6 Operations Working Group (v6ops) F. Gont IPv6 Operations Working Group (v6ops) F. Gont
Internet-Draft SI6 Networks Internet-Draft SI6 Networks
Intended status: Informational J. Zorz Intended status: Informational J. Zorz
Expires: August 22, 2020 Go6 Institute Expires: September 10, 2020 Go6 Institute
R. Patterson R. Patterson
Sky UK Sky UK
February 19, 2020 March 9, 2020
Improving the Reaction of Customer Edge Routers to Renumbering Events Improving the Reaction of Customer Edge Routers to Renumbering Events
draft-ietf-v6ops-cpe-slaac-renum-00 draft-ietf-v6ops-cpe-slaac-renum-01
Abstract Abstract
In scenarios where network configuration information related to IPv6 In scenarios where network configuration information related to IPv6
prefixes becomes invalid without any explicit signaling of that prefixes becomes invalid without any explicit signaling of that
condition (such as when a Customer Edge Router crashes and reboots condition (such as when a Customer Edge Router crashes and reboots
without knowledge of the previously-employed prefixes), hosts on the without knowledge of the previously-employed prefixes), hosts on the
local network will continue using stale prefixes for an unacceptably local network will continue using stale prefixes for an unacceptably
long period of time, thus resulting in connectivity problems. This long period of time, thus resulting in connectivity problems. This
document specifies improvements to Customer Edge Routers that help document specifies improvements to Customer Edge Routers that help
skipping to change at page 1, line 41 skipping to change at page 1, line 41
Internet-Drafts are working documents of the Internet Engineering Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet- working documents as Internet-Drafts. The list of current Internet-
Drafts is at https://datatracker.ietf.org/drafts/current/. Drafts is at https://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress." material or to cite them other than as "work in progress."
This Internet-Draft will expire on August 22, 2020. This Internet-Draft will expire on September 10, 2020.
Copyright Notice Copyright Notice
Copyright (c) 2020 IETF Trust and the persons identified as the Copyright (c) 2020 IETF Trust and the persons identified as the
document authors. All rights reserved. document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents Provisions Relating to IETF Documents
(https://trustee.ietf.org/license-info) in effect on the date of (https://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents publication of this document. Please review these documents
skipping to change at page 2, line 19 skipping to change at page 2, line 19
the Trust Legal Provisions and are provided without warranty as the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License. described in the Simplified BSD License.
Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Improved Customer Edge Router Behavior . . . . . . . . . . . 2 2. Improved Customer Edge Router Behavior . . . . . . . . . . . 2
2.1. Interface Between DHCPv6-PD and SLAAC . . . . . . . . . . 3 2.1. Interface Between DHCPv6-PD and SLAAC . . . . . . . . . . 3
2.2. Signaling Stale Configuration Information . . . . . . . . 3 2.2. Signaling Stale Configuration Information . . . . . . . . 3
3. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 4 3. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 4
4. Security Considerations . . . . . . . . . . . . . . . . . . . 5 4. Security Considerations . . . . . . . . . . . . . . . . . . . 4
5. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 5 5. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 4
6. References . . . . . . . . . . . . . . . . . . . . . . . . . 5 6. References . . . . . . . . . . . . . . . . . . . . . . . . . 5
6.1. Normative References . . . . . . . . . . . . . . . . . . 5 6.1. Normative References . . . . . . . . . . . . . . . . . . 5
6.2. Informative References . . . . . . . . . . . . . . . . . 6 6.2. Informative References . . . . . . . . . . . . . . . . . 5
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 6 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 6
1. Introduction 1. Introduction
In scenarios where network configuration information related to IPv6 In scenarios where network configuration information related to IPv6
prefixes becomes invalid without any explicit signaling of that prefixes becomes invalid without any explicit signaling of that
condition, nodes on the local network will continue using stale condition, nodes on the local network will continue using stale
prefixes for an unacceptably long period of time, thus resulting in prefixes for an unacceptably long period of time, thus resulting in
connectivity problems. This problem is documented in detail in connectivity problems. This problem is documented in detail in
[I-D.gont-v6ops-slaac-renum]. [I-D.gont-v6ops-slaac-renum].
skipping to change at page 3, line 9 skipping to change at page 3, line 9
Section 1. This would obviously make robustness dependent on the Section 1. This would obviously make robustness dependent on the
Customer Edge Router (on which the user or ISP may have no control), Customer Edge Router (on which the user or ISP may have no control),
as opposed to the host itself. as opposed to the host itself.
The updated behaviour is as follows: The updated behaviour is as follows:
o CE routers MUST signal stale configuration information as o CE routers MUST signal stale configuration information as
specified in Section 2.2 specified in Section 2.2
o CE routers MUST implement the DHCPv6-PD/SLAAC interface specified o CE routers MUST implement the DHCPv6-PD/SLAAC interface specified
in Section 2.1. in Section 2.1
o CE routers SHOULD NOT automatically send DHCPv6-PD RELEASE o CE routers SHOULD NOT automatically send DHCPv6-PD RELEASE
messages upon reboot events. messages upon reboot events
2.1. Interface Between DHCPv6-PD and SLAAC 2.1. Interface Between DHCPv6-PD and SLAAC
The "Preferred Lifetime" and "Valid Lifetime" of Prefix Information The "Preferred Lifetime" and "Valid Lifetime" of Prefix Information
Options (PIOs) [RFC4861] corresponding to prefixes learned via Options (PIOs) [RFC4861] corresponding to prefixes learned via
DHCPv6-PD MUST NOT span past the lease time of the DHCPv6-PD DHCPv6-PD MUST NOT span past the lease time of the DHCPv6-PD
prefixes. This means that the advertised "Preferred Lifetime" and prefixes. This means that the advertised "Preferred Lifetime" and
"Valid Lifetime" MUST be dynamically adjusted such that the "Valid Lifetime" MUST be dynamically adjusted such that the
advertised lifetimes never span past the lease time of the prefixes advertised lifetimes never span past the lease time of the prefixes
delegated via DHCPv6-PD. delegated via DHCPv6-PD.
skipping to change at page 3, line 52 skipping to change at page 4, line 4
(rather than static values), since otherwise the advertised (rather than static values), since otherwise the advertised
lifetimes would eventually span past the DHCPv6-PD lease time. lifetimes would eventually span past the DHCPv6-PD lease time.
2.2. Signaling Stale Configuration Information 2.2. Signaling Stale Configuration Information
In order to phase-out stale configuration information: In order to phase-out stale configuration information:
o A CE router sending RAs that advertise dynamically-learned o A CE router sending RAs that advertise dynamically-learned
prefixes (e.g. via DHCPv6-PD) on an interface MUST record, on prefixes (e.g. via DHCPv6-PD) on an interface MUST record, on
stable storage, the list of prefixes being advertised on each stable storage, the list of prefixes being advertised on each
network segment. network segment, and the "A" and "L" flags of the corresponding
PIOs.
o Upon changes to the advertised prefixes, and after bootstrapping, o Upon changes to the advertised prefixes, and after bootstrapping,
the CE router advertising prefix information via SLAAC should the CE router advertising prefix information via SLAAC should
proceed as follows: proceed as follows:
* Any prefixes that were previously advertised via Router * Any prefixes that were previously advertised via Router
Advertisement (RA) messages for address configuration, but that Advertisement (RA) messages, but that have now become stale,
are not currently intended for address configuration, MUST be MUST be advertised with a "Valid Lifetime" and a "Preferred
advertised with a PIO with the "A" bit set to 1 and the "Valid Lifetime" set to 0, and the "A" and "L" bits unchanged.
Lifetime" and a "Preferred Lifetime" set to 0.
* Any prefixes that were previously advertised via RA messages as
"on-link", but that are not currently not considered "on-link",
MUST be advertised with a PIO with the "L" bit set to 1 and the
"Valid Lifetime" and a "Preferred Lifetime" set to 0.
* If both of the previous conditions are met (a prefix was
previously advertised with both the "A" and "L" bits set, but
is currently *not* intended for address configuration and is
*not* considered on-link), the prefix MUST be advertised with a
PIO option with both the "A" and "L" bits set to 1 and the
"Valid Lifetime" and a "Preferred Lifetime" set to 0. That is.
the advertisements of the previous two steps can be coalesced
into a single one with both the "A" and "L" bits set.
* The aforementioned advertisement SHOULD be performed for at * The aforementioned advertisement SHOULD be performed for at
least the "Valid Lifetime" previously employed for such prefix. least the "Valid Lifetime" previously employed for such prefix.
The aforementioned improved behaviour assumes compliance with the The aforementioned improved behaviour assumes compliance with the
following existing requirements from other specifications, which we following existing requirements from other specifications, which we
reference here for clarity: reference here for clarity:
o [RFC7084] specifies (requirement LE-13, in Section 4.3) that when o [RFC7084] specifies (requirement LE-13, in Section 4.3) that when
the delegated prefix changes (i.e., the current prefix is replaced the delegated prefix changes (i.e., the current prefix is replaced
skipping to change at page 6, line 16 skipping to change at page 5, line 44
[I-D.gont-6man-slaac-renum] [I-D.gont-6man-slaac-renum]
Gont, F., Zorz, J., and R. Patterson, "Improving the Gont, F., Zorz, J., and R. Patterson, "Improving the
Robustness of Stateless Address Autoconfiguration (SLAAC) Robustness of Stateless Address Autoconfiguration (SLAAC)
to Flash Renumbering Events", draft-gont-6man-slaac- to Flash Renumbering Events", draft-gont-6man-slaac-
renum-02 (work in progress), February 2020. renum-02 (work in progress), February 2020.
[I-D.gont-v6ops-slaac-renum] [I-D.gont-v6ops-slaac-renum]
Gont, F., Zorz, J., and R. Patterson, "Reaction of Gont, F., Zorz, J., and R. Patterson, "Reaction of
Stateless Address Autoconfiguration (SLAAC) to Flash- Stateless Address Autoconfiguration (SLAAC) to Flash-
Renumbering Events", draft-gont-v6ops-slaac-renum-01 (work Renumbering Events", draft-gont-v6ops-slaac-renum-02 (work
in progress), November 2019. in progress), February 2020.
[RFC7084] Singh, H., Beebee, W., Donley, C., and B. Stark, "Basic [RFC7084] Singh, H., Beebee, W., Donley, C., and B. Stark, "Basic
Requirements for IPv6 Customer Edge Routers", RFC 7084, Requirements for IPv6 Customer Edge Routers", RFC 7084,
DOI 10.17487/RFC7084, November 2013, DOI 10.17487/RFC7084, November 2013,
<https://www.rfc-editor.org/info/rfc7084>. <https://www.rfc-editor.org/info/rfc7084>.
Authors' Addresses Authors' Addresses
Fernando Gont Fernando Gont
SI6 Networks SI6 Networks
 End of changes. 11 change blocks. 
30 lines changed or deleted 16 lines changed or added

This html diff was produced by rfcdiff 1.47. The latest version is available from http://tools.ietf.org/tools/rfcdiff/