Logo
ICANN
ICANN
Filtered Search

Are you sure you want to sign out from http://www.icann.org?

If you want to sign out from both http://www.icann.org and ICANN Account, click here.

Public Comment

Public Comment is a vital part of our multistakeholder model. It provides a mechanism for stakeholders to have their opinions and recommendations formally and publicly documented. It is an opportunity for the ICANN community to effect change and improve policies and operations.

Ce contenu est uniquement disponible en

  • English

Name: Mark Smith
Date: 29 Oct 2025
Affiliation: IETF
Email: [email protected]
Original Public Comment: Name Collision IPv6 Research Study
Other Comments

The IETF 6man and v6ops working groups have been forwarded this proposal, as reserving IPv6 (and IPv4) address space for special purposes is the responsiblity and authority of the IETF and the Internet Assigned Number Authority (IANA).


You can browse the discussions at https://mailarchive.ietf.org/arch/browse/ipv6/ (6man) and https://mailarchive.ietf.org/arch/browse/v6ops/ (v6ops), and join the mailing lists at https://datatracker.ietf.org/wg/6man/about/ and https://datatracker.ietf.org/wg/v6ops/about/ to participate in those discussions.


The current consensus seems to be:


This proposal should be submitted as an Internet Draft, as that is the way that the IETF deal with any and all proposals, including the assigning IPv4 and IPv6 addresses with special purposes. https://datatracker.ietf.org/doc/draft-smith-v6ops-larger-ipv6-loopback-prefix/04/ is an example of such a proposal.


The use of any loopback addresses, either IPv4, IPv6, or IPv4 loopback addresses embedded in an IPv6 address is not appropriate for this purpose.


The use of 127.0.53.53 for this purpose is unofficial, as there was never any IETF review or assignment of that address for this purpose in the IANA IPv4 Special-Purpose Address Space registry.


https://www.iana.org/assignments/iana-ipv4-special-registry/iana-ipv4-special-registry.xhtml


It would be better to write an Internet Draft that proposed IPv4 and IPv6 address space for this purpose that did not interfere with any existing reserved IPv4 or IPv6 address space, and submit that Internet Draft to the IETF v6ops working group.


The reserved IPv6 address space is shown at the following:


https://www.iana.org/assignments/ipv6-address-space/ipv6-address-space.xhtml


while the IPv4 address space is shown at:


https://www.iana.org/assignments/ipv4-address-space/ipv4-address-space.xhtml


Regards,

Mark.

Summary of Submission

This proposal needs to be made via the an Internet Draft submitted to the IETF v6ops working group. Only IANA can assign special purposes to IPv4 and IPv6 addresses after IETF review and approval.