[HEADSUP] Re: Is IPV6 option still necessary?

Jeremy Chadwick jdc at koitsu.org
Thu Oct 10 03:20:11 UTC 2019

> Now we can get back on the ipv6 option.
> so if we want to proceed further in removing the option to build with or without
> ipv6 for the ports side. Please speak up in reply to this email, if you are
> building without ipv6, why are you doing so, what are the real benefit for it.
> How bad it will impact you if we do remove that option?

Whenever I use ports over FreeBSD-provided packages (or to use ports to
build my own packages), I often disable IPV6 support.  The lengthy
response below should explain why.

In short: the IPV6 option is useful and important.  Please keep it.

In length: I think anyone operating in the Real World knows quite well
that IPv6 is still treated as a third-class citizen when it comes to
both general connectivity/reliability* and general use cases
code-wise**.  It's still very much in utero; or a toddler, if you will.

When you encounter IPv6 vs. IPv4 prioritisation issues, they are painful
and annoying.  No user or administrator is going to sit for hours
fiddling with it all to restore things to a working state when simply
removing IPv6 relieves the problem permanently.  Time and time again I
see companies advertising AAAA records and webservers listening on IPv6
yet IPv6 transit fails but their A/IPv4 endpoint works fine.  It's the
dual-stack nature that makes a lot of this worse than it should be.  (I
do think this subject should be re-visited once the world as a whole
starts to seriously decommission IPv4, though.  Yes I'm serious.)

I've worked for several companies that are IPv4-only, where the belief
(and one I share) is that IPv6-only clients have some 6-to-4-ish
gateway/NAT somewhere upstream, otherwise they wouldn't be able to reach
most of the Internet.  IPv4 NAT still works for the majority of use
cases still as of 2019.

Furthermore, faux-political statements like "IPv6 is more widely used
than 2012" should be ignored and facts reiterated: IPv6 adoption is
around 25% as of mid-2019.  And it's taken over 10 years to reach that.

IPv4 is also well-understood, and not, as Dave Horsfall accurately
described, "a horse designed by a committee"; people are still trying to
wrap their head around IPv6 NDP/RA, SLAAC, and a myriad of other things
(dare I mention syntax?).  It's this which explains the sluggish
adoption rate.

And yes, I am well-aware of how important IPv6 is in other regions,
particularly Asia.  I am not belittling that need at all.  But not
everyone globally has the same needs.

What should really be asked for is the opposite: for the FreeBSD ports
folks to justify its removal.

How is this hurting you on a daily basis?  Is there a large percentage
of Mk/ framework bits causing you pain?  Are the bulk of per-port
patches inducing maintainer grief?  At what scale is this impacting you?
In 7 years (since the OP picked 2012), how much time has been spent by
maintainers ensuring IPV6=true works for their port(s)?  Are you truly
OK throwing away the integration work done by many, many people (not
just Project members!) over the past N years (see: per-port patches),
and forcing people who still need the option to make their own ports
tree to retain it?

Here's some harsh advice for the FreeBSD Project: quit changing shit for
sake of change, often masked by lies like "XXX is stagnant/old" or
similarly fallacious and loaded statements.  The project (both src and
ports, but especially ports) have lost many very good people in the past
10+ years (and I'm not talking about me) *because* of that change for
sake of change mindset -- the same mindset driving this request!  It's
changes like this that drive people away from FreeBSD.  Really.  It's
the same mindset that provoked people to stop using Linux distros due
to systemd integration.

I will not be replying to this thread past this point.  I have said all
that I care to say / spent enough time on it.  Just please stop hurting
administrators and end users with proposals/actions like this.

* - Real-world IPv6 failures impacting end users tend to be higher
than IPv4; this is anecdotal on my part, but I have a myriad of peers
who have had to disable IPv6 for similar reasons.  The IPv4 fallback in
software (both userland apps and network stacks) does not always work
"correctly".  Just go see how often IPv6 failures/issues are reported on
both NANOG and the outages@ mailing list.  And yes I am quite aware that
a good portion of the Internet backbone at this point is IPv6 (that's
nice, and not what we're talking about here).

** - I still continue to see open-source software committing major fixes
to AF_INET6 related code bits.  Major pieces of software include curl,
wget, Busybox, DNS servers (pick one!), and ntp... just for starters.

| Jeremy Chadwick                                 jdc at koitsu.org |
| UNIX Systems Administrator                      PGP 0x2A389531 |
| Making life hard for others since 1977.                        |

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