Subject: Re: HEADS UP! Default value of ip6_v6only changed
To: NetBSD OS PMC <firstname.lastname@example.org>
From: William Allen Simpson <email@example.com>
Date: 10/28/2003 04:54:30
NetBSD OS PMC wrote:
> The default value of ip6_v6only (sysctl net.inet6.ip6.v6only) has
> been changed. The new value brings us closer in line with current
> RFC-defined behavior and practices.
> Itojun still has significant concerns about the new default behavior.
> His concerns have been well-documented in
> Best Regards,
> NetBSD OS PMC (core)
The draft is well founded. I strongly opposed the translation/mapping
of IPv4 into IPv6 a decade ago. There was a whole working group
devoted to the project, and AFAIK, the WG failed interoperability and
The stack should use IPv4 or IPv6 on a per host basis, as indicated by
its DNS *and* the availability of IPv6 infrastructure, but not both
concurrently (for a host). Of course, there could be IPv4 and IPv6
concurrently (dual stack approach).
Craig Metz is a sharp fellow, and has been working on IPv6
implementation since the beginning. We all respect itojun (of course).
RFCs are not gospel. RFC-2133/2553/3493 has evolved over time, and is
"Informational". The new IPV6_V6ONLY is only in the most recent
version, and the default value of "off" is manifestly wrong.
Please leave the default value as "on", as recommended by
William Allen Simpson
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