draft-schoen-intarea-unicast-240-06.txt | draft-schoen-intarea-unicast-240-07.txt | |||
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Internet Engineering Task Force S.D. Schoen | Internet Engineering Task Force S.D. Schoen | |||
Internet-Draft J. Gilmore | Internet-Draft J. Gilmore | |||
Updates: 1122, 3704, 6890 (if approved) D. Täht | Updates: 1122, 3704, 6890 (if approved) D. Täht | |||
Intended status: Standards Track IPv4 Unicast Extensions Project | Intended status: Standards Track IPv4 Unicast Extensions Project | |||
Expires: 1 July 2024 29 December 2023 | Expires: 30 December 2024 28 June 2024 | |||
Unicast Use of the Formerly Reserved 240/4 | Unicast Use of the Formerly Reserved 240/4 | |||
draft-schoen-intarea-unicast-240-06 | draft-schoen-intarea-unicast-240-07 | |||
Abstract | Abstract | |||
This document redesignates 240/4, the region of the IPv4 address | This document redesignates 240/4, the region of the IPv4 address | |||
space historically known as "Experimental," "Future Use," or "Class | space historically known as "Experimental," "Future Use," or "Class | |||
E" address space, so that this space is no longer reserved. It asks | E" address space, so that this space is no longer reserved. It asks | |||
implementers to make addresses in this range fully usable for unicast | implementers to make addresses in this range fully usable for unicast | |||
use on the Internet. | use on the Internet. | |||
Status of This Memo | Status of This Memo | |||
skipping to change at page 1, line 35 ¶ | skipping to change at page 1, line 35 ¶ | |||
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 1 July 2024. | This Internet-Draft will expire on 30 December 2024. | |||
Copyright Notice | Copyright Notice | |||
Copyright (c) 2023 IETF Trust and the persons identified as the | Copyright (c) 2024 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 (https://trustee.ietf.org/ | Provisions Relating to IETF Documents (https://trustee.ietf.org/ | |||
license-info) in effect on the date of publication of this document. | license-info) in effect on the date of publication of this document. | |||
Please review these documents carefully, as they describe your rights | Please review these documents carefully, as they describe your rights | |||
and restrictions with respect to this document. Code Components | and restrictions with respect to this document. Code Components | |||
extracted from this document must include Revised BSD License text as | extracted from this document must include Revised BSD License text as | |||
described in Section 4.e of the Trust Legal Provisions and are | described in Section 4.e of the Trust Legal Provisions and are | |||
provided without warranty as described in the Revised BSD License. | provided without warranty as described in the Revised BSD License. | |||
skipping to change at page 2, line 28 ¶ | skipping to change at page 2, line 28 ¶ | |||
6. Security Considerations . . . . . . . . . . . . . . . . . . . 10 | 6. Security Considerations . . . . . . . . . . . . . . . . . . . 10 | |||
6.1. Existing Unofficial Uses of 240/4 . . . . . . . . . . . . 11 | 6.1. Existing Unofficial Uses of 240/4 . . . . . . . . . . . . 11 | |||
7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 12 | 7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 12 | |||
8. References . . . . . . . . . . . . . . . . . . . . . . . . . 12 | 8. References . . . . . . . . . . . . . . . . . . . . . . . . . 12 | |||
8.1. Normative References . . . . . . . . . . . . . . . . . . 12 | 8.1. Normative References . . . . . . . . . . . . . . . . . . 12 | |||
8.2. Informative References . . . . . . . . . . . . . . . . . 13 | 8.2. Informative References . . . . . . . . . . . . . . . . . 13 | |||
Appendix A. Implementation Status . . . . . . . . . . . . . . . 16 | Appendix A. Implementation Status . . . . . . . . . . . . . . . 16 | |||
A.1. Operating systems . . . . . . . . . . . . . . . . . . . . 16 | A.1. Operating systems . . . . . . . . . . . . . . . . . . . . 16 | |||
A.2. Routers and Switches . . . . . . . . . . . . . . . . . . 17 | A.2. Routers and Switches . . . . . . . . . . . . . . . . . . 17 | |||
A.3. DHCP implementations . . . . . . . . . . . . . . . . . . 18 | A.3. DHCP implementations . . . . . . . . . . . . . . . . . . 18 | |||
A.4. Other implementations . . . . . . . . . . . . . . . . . . 18 | A.4. Other implementations . . . . . . . . . . . . . . . . . . 19 | |||
A.5. Internet of Things . . . . . . . . . . . . . . . . . . . 18 | A.5. Internet of Things . . . . . . . . . . . . . . . . . . . 19 | |||
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 18 | Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 19 | |||
1. Introduction | 1. Introduction | |||
With ever-increasing pressure to conserve IP address space on the | With ever-increasing pressure to conserve IP address space on the | |||
Internet, it makes sense to consider where relatively minor changes | Internet, it makes sense to consider where relatively minor changes | |||
can be made to fielded practice to improve numbering efficiency. One | can be made to fielded practice to improve numbering efficiency. One | |||
such change, proposed by this document, is to redefine the | such change, proposed by this document, is to redefine the | |||
"Experimental" or "Future Use" 240/4 region (historically known as | "Experimental" or "Future Use" 240/4 region (historically known as | |||
"Class E" addresses) as ordinary unicast addresses. These 268 | "Class E" addresses) as ordinary unicast addresses. These 268 | |||
million IPv4 addresses are already usable for unicast traffic in many | million IPv4 addresses are already usable for unicast traffic in many | |||
skipping to change at page 12, line 15 ¶ | skipping to change at page 12, line 15 ¶ | |||
Operators of networks that are making unofficial uses of portions of | Operators of networks that are making unofficial uses of portions of | |||
240/4 may wish to plan to discontinue these uses and renumber their | 240/4 may wish to plan to discontinue these uses and renumber their | |||
internal networks, or to request that IANA formally designate certain | internal networks, or to request that IANA formally designate certain | |||
ranges as additional Private-Use areas. | ranges as additional Private-Use areas. | |||
7. Acknowledgements | 7. Acknowledgements | |||
This document directly builds on prior work by Dave Täht and John | This document directly builds on prior work by Dave Täht and John | |||
Gilmore as part of the IPv4 Unicast Extensions Project. | Gilmore as part of the IPv4 Unicast Extensions Project. | |||
We thank our late colleague Michael J. Karels (1956-2024) for his | ||||
comments on this draft and related FreeBSD implementation efforts. | ||||
8. References | 8. References | |||
8.1. Normative References | 8.1. Normative References | |||
[IANA4] Internet Assigned Numbers Authority, "IANA IPv4 Special- | [IANA4] Internet Assigned Numbers Authority, "IANA IPv4 Special- | |||
Purpose Address Registry", | Purpose Address Registry", | |||
<https://www.iana.org/assignments/iana-ipv4-special- | <https://www.iana.org/assignments/iana-ipv4-special- | |||
registry/iana-ipv4-special-registry.xhtml>. | registry/iana-ipv4-special-registry.xhtml>. | |||
[RFC0870] Reynolds, J. and J. Postel, "Assigned numbers", RFC 870, | [RFC0870] Reynolds, J. and J. Postel, "Assigned numbers", RFC 870, | |||
skipping to change at page 13, line 39 ¶ | skipping to change at page 13, line 44 ¶ | |||
ipv4#ipv4_routable_240.0.0.0_4>. | ipv4#ipv4_routable_240.0.0.0_4>. | |||
[Atlas] RIPE Network Coordination Centre, "RIPE Atlas", | [Atlas] RIPE Network Coordination Centre, "RIPE Atlas", | |||
<https://atlas.ripe.net/>. | <https://atlas.ripe.net/>. | |||
[Cloudflare] | [Cloudflare] | |||
Strong, M., "Fixing reachability to 1.1.1.1, GLOBALLY!", 4 | Strong, M., "Fixing reachability to 1.1.1.1, GLOBALLY!", 4 | |||
April 2018, <https://blog.cloudflare.com/fixing- | April 2018, <https://blog.cloudflare.com/fixing- | |||
reachability-to-1-1-1-1-globally/>. | reachability-to-1-1-1-1-globally/>. | |||
[Cox] Cartwright-Cox, B. and Z. Pospíchal, "On "Reclaiming" | ||||
240.0.0.0/4", 23 May 2024, | ||||
<https://ripe88.ripe.net/archives/video/1367/>. | ||||
[Dale] Dale, L. and F. Korsbäck, "Dive Deep on AWS Networking | [Dale] Dale, L. and F. Korsbäck, "Dive Deep on AWS Networking | |||
Infrastructure (presentation)", NANOG88, June 2023, | Infrastructure (presentation)", NANOG88, June 2023, | |||
<https://www.youtube.com/watch?v=0tcR-iQce7s&t=1709s>. | <https://www.youtube.com/watch?v=0tcR-iQce7s&t=1709s>. | |||
[FLM] Fuller, V., Lear, E., and D. Meyer, "Reclassifying 240/4 | [FLM] Fuller, V., Lear, E., and D. Meyer, "Reclassifying 240/4 | |||
as usable unicast address space", Work in Progress, | as usable unicast address space", Work in Progress, | |||
Internet-Draft, draft-fuller-240space-02, 25 March 2008, | Internet-Draft, draft-fuller-240space-02, 25 March 2008, | |||
<https://datatracker.ietf.org/doc/html/draft-fuller- | <https://datatracker.ietf.org/doc/html/draft-fuller- | |||
240space-02>. | 240space-02>. | |||
skipping to change at page 17, line 33 ¶ | skipping to change at page 17, line 40 ¶ | |||
We have prepared a patch which enables 240/4 support this on NetBSD. | We have prepared a patch which enables 240/4 support this on NetBSD. | |||
It has not been merged as of December 2023. | It has not been merged as of December 2023. | |||
240/4 traffic is blocked by default in all versions of the Microsoft | 240/4 traffic is blocked by default in all versions of the Microsoft | |||
Windows operating system. Windows will not assign an interface | Windows operating system. Windows will not assign an interface | |||
address in this range, if one is offered by DHCP. | address in this range, if one is offered by DHCP. | |||
A.2. Routers and Switches | A.2. Routers and Switches | |||
Unless otherwise noted, support in this section reflects interface | ||||
assignment and packet-forwarding support, not BGP support, which may | ||||
involve separate bogon logic. | ||||
240/4 has been tested to interoperate as ordinary unicast in 2019 in | 240/4 has been tested to interoperate as ordinary unicast in 2019 in | |||
a Cisco router using IOS release 6.5.2.28I, which was also released | a Cisco router using IOS release-XR 6.5.2.28I, which was also | |||
in 2019. Older and newer releases are also likely to work. | released in 2019. Older and newer releases are also likely to work. | |||
Cisco also has two other router OS variants which have not been | ||||
tested. | ||||
240/4 traffic is blocked by default in Juniper's router operating | 240/4 traffic is blocked by default in Juniper's router operating | |||
system, but can be enabled with a simple configuration switch, | system, but can be enabled with a simple configuration switch, | |||
starting from the JUNOS 9.6 release in June 2010. See page 50 of | starting from the JUNOS 9.6 release in June 2010. See page 50 of | |||
[JUNOS-release-notes-9.6]. It notes, "The JUNOS Software now allows | [JUNOS-release-notes-9.6]. It notes, "The JUNOS Software now allows | |||
Class E addresses to be configured on interfaces. To allow Class E | Class E addresses to be configured on interfaces. To allow Class E | |||
addresses to be configured on interfaces, remove the Class E prefix | addresses to be configured on interfaces, remove the Class E prefix | |||
from the list of martian addresses by including the [edit routing- | from the list of martian addresses by including the [edit routing- | |||
options martians 240/4 orlonger allow] configuration statement." See | options martians 240/4 orlonger allow] configuration statement." See | |||
also chapter 5, "Martian Addresses" on page 129 through 136 of the | also chapter 5, "Martian Addresses" on page 129 through 136 of the | |||
2022 documentation [JUNOS-routing-properties]. It includes a | 2022 documentation [JUNOS-routing-properties]. It includes a | |||
completely worked example on "Removing the Class E Prefix on Martian | completely worked example on "Removing the Class E Prefix on Martian | |||
Addresses". | Addresses". | |||
Arista switches running EOS 4.25.2F (from February 2021), and later | Arista switches running EOS 4.25.2F (from February 2021), and later | |||
releases, include the command "ipv4 routable 240.0.0.0/4" which | releases, include the command "ipv4 routable 240.0.0.0/4" which | |||
enables the use of 240/4 addresses on interfaces and in packet | enables the use of 240/4 addresses on interfaces and in packet | |||
routing. The default is to disable this ability. | routing. The default is to disable this ability. | |||
[Arista-user-manual] | [Arista-user-manual] | |||
The Belkin AX3200 router (with firmware 1.0.01 build 101415 Oct 14, | The Belkin AX3200 router (with firmware 1.0.01 build 101415 Oct 14, | |||
2020) cannot use addresses from 240/4 locally, but is happy to route | 2020) cannot use addresses from 240/4 locally, but is happy to route | |||
packets to such addresses elsewhere in the Internet. | packets to such addresses elsewhere in the Internet. | |||
A 2024 presentation by Ben Cartwright-Cox [Cox] reported on his | ||||
experiments on support for 240/4 in several router environments | ||||
(including BGP). According to Cartwright-Cox, RouterOS 7.7 and IOS | ||||
XR fully support 240/4. Arista(v)EOS 4.29.0.2F allows opting in to | ||||
240/4 support and is believed to work when this is enabled, although | ||||
it could not be fully tested in Cartwright-Cox's virtualized | ||||
environment. JunOS 22.X similarly allows opting in to 240/4 support, | ||||
and can properly use and route addresses in this range statically and | ||||
dynamically, although its built-in DHCP server is not willing to | ||||
assign them to other devices on a locally attached network. Finally, | ||||
EXOS 31.1.1.6-1, IOS XE, Nokia SR-OS, and Huawei VRP generally did | ||||
not support using or routing 240/4, while the latter three exhibited | ||||
an apparent bug in which they would ostensibly accept dynamic routes | ||||
within 240/4 but not actually apply these into the RIB or FIB. | ||||
A.3. DHCP implementations | A.3. DHCP implementations | |||
Support for 240/4 addressing may be typical of many DHCP | Support for 240/4 addressing may be typical of many DHCP | |||
implementations (because the 240/4 address assignment special case | implementations (because the 240/4 address assignment special case | |||
has often been handled at the kernel level). If the underlying | has often been handled at the kernel level). If the underlying | |||
operating system supports 240/4 assignment to an interface, the final | operating system supports 240/4 assignment to an interface, the final | |||
official ISC DHCP release (4.4.3) supports 240/4 allocation as both | official ISC DHCP release (4.4.3) supports 240/4 allocation as both | |||
client and server, as do Busybox DHCP udhcpc/udhcpd (release 1.1.15), | client and server, as do Busybox DHCP udhcpc/udhcpd (release 1.1.15), | |||
and ISC Kea (which currently includes only a DHCP server | and ISC Kea (which currently includes only a DHCP server | |||
implementation). | implementation). | |||
End of changes. 11 change blocks. | ||||
9 lines changed or deleted | 38 lines changed or added | |||
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