Re: IPv4 flag day

[Tom Beecher via NANOG <nanog () lists nanog org>]

> It is unfortunate that it worked out this way, but if we're going to
> shut one of them off it should be IPv6 - the one that's adding no
> benefit for anybody

"no benefit for anybody" is an entirely incorrect statement.

just cost, complexity and reduced reliability.


Many who make the cost argument state that it's too expensive to swap out
entire hardware and software stacks 'just for V6 support'. While that's
probably true, it ignores that nobody actually has to do that. Everyone
goes through hardware and software replacement cycles. All anyone has to do
is require that the hardware and software they select in those cycles
support V6. Eventually everything supports it, and you've had time to
familiarize yourself to operate it.

One could also reasonably argue that reliability is *improved* with V6,
purely from the fact that all flavors of NAT are removed from the
connectivity path. This is important to those that care about such things,
but to everyone who thinks the current state is 'good enough', they likely
consider this to be an academic argument.

Yet this is what people have been working on for the past 10
> years to try to make IPv6 appear relevant.


IPv6 became a draft standard 28 years ago. Since that point, more work has
gone into extending the transition mechanisms intended to be temporary into
full fledged workarounds to NOT use V6.

 If there were a benefit to
> gain from IPv6 then most would have migrated to it already.


Translations :
- "I have enough V4 space for my needs, anyone who doesn't can pound sand."
- "I have been able to leverage workarounds so I can look good by never
spending any money."
- "The users of my networks never touch anything V6 so I don't have to
care."

These are all great answers if they apply to you, until they don't, and
your bosses are up your ass to make it work.  Might end up being career
limiting events for some when their bosses find out they had a 30 year
window to avoid it.

But the biggest turnoff is
> the group of people who reply to every networking thread with "IPv6 IPv6
> IPv6" even when it's not relevant.  There is even coercive language like
> "legacy internet" being thrown around.  This has turned into dogmatic
> loaded framing rather than engineering.


On this point I agree with you. Stating that V6 is the 'answer' to a given
challenge when it's not is unhelpful.

At the end of the day , IPv4 and IPv6 are both standard addressing
protocols used across the internet. That isn't going to change at this
point anytime in any of our careers, and probably won't in the next
generation's careers either.

You have 3 choices.

   1. Build a network that supports both.
   2. Build a network that supports V4 only with a translation mechanism to
   talk to V6 should it be required, and hope that's good enough.
   3. Build a network that supports V4 only and hope V6 never causes an
   issue.

You will spend time and money no matter which way you go. How much and when
that bill becomes due is the only difference.



On Tue, Jun 16, 2026 at 9:26 AM Laszlo H via NANOG <nanog () lists nanog org>
wrote:

> It is unfortunate that it worked out this way, but if we're going to
> shut one of them off it should be IPv6 - the one that's adding no
> benefit for anybody - just cost, complexity and reduced reliability.
> The idea of intentionally hobbling IPv4 precisely because it works, in
> order to make IPv6 look more appealing, is a perverse and bad faith
> approach.  Yet this is what people have been working on for the past 10
> years to try to make IPv6 appear relevant.  If there were a benefit to
> gain from IPv6 then most would have migrated to it already.  At this
> point it's just a few zealots who are trying to figure out how to
> undermine IPv4 at scale, so IPv6 becomes the next best choice.  The
> decisions to make things different from IPv4 are not helping either
> (RA/DHCP, multiple routers and the like).  But the biggest turnoff is
> the group of people who reply to every networking thread with "IPv6 IPv6
> IPv6" even when it's not relevant.  There is even coercive language like
> "legacy internet" being thrown around.  This has turned into dogmatic
> loaded framing rather than engineering.
>
> -Laszlo
>
> On 6/16/26 12:37 PM, Douglas Fischer via NANOG wrote:
> > The goal isn't to shut down IPv4, it's to let it starve to death.
> > I didn't receive a document saying I should disable NETBEUI or IPX/SPX on
> > my networks.
> >
> > IMHO
> > I believe the focus of the effort should be on causing technical
> discomfort
> > and embarrassment to those who maintain applications that are not yet
> > capable of providing interoperability between clients that are on IPv4
> and
> > clients that are on IPv6.
> >
> > And in my view, the biggest villains in this case are the gaming
> platforms.
> > Making these guys abandon the exclusively legacy methodology and focus on
> > IPv6 is one of the keys that will begin to remove the last shackles to
> > allow the end user to be on IPv6 only and not even know that IPv4 and
> IPv6
> > exist.
> >
> >
> > Em ter., 16 de jun. de 2026 às 03:34, Saku Ytti via NANOG <
> > nanog () lists nanog org> escreveu:
> >
> > > 'ello,
> > >
> > > I've babbled about this before, but apparently I'm babbling about it
> again.
> > > Does anyone feel responsibility for the dual stack mess we've created?
> > > It wasn't here when we found the Internet, and we're going to leave it
> > > here after we leave, does not really jive with the whole leave
> > > campground cleaner than found it ethos.
> > >
> > > I don't see any future where organically IPv4 dies in such a way that
> > > people offering services on the Internet are comfortable offering them
> > > IPv6 only, the long tail will be too expensive to ignore.
> > >
> > > Dual stack adds complexity, cost, reduces quality and security. It is
> > > also blatantly an antitrust issue, as established players with access
> > > to large allocations can outcompete new entrants with no IPv4
> > > allocation.
> > >
> > > In practice I'm thinking about something where relevant players all
> > > sign an agreement to drop ipv4 at their edge in e..g 15 or 20 years.
> > > Creating clear business justification for people to implement IPv6 in
> > > their next upgrade cycle. Today if I'm an edge with the IPv4 addresses
> > > I need, I wouldn't consider IPv6, because that's just a cost to me,
> > > with no upside.
> > > I know I could get some transit shops to sign off on such an
> > > agreement, but no one cares about transit, this obviously doesn't work
> > > without Amazon and Facebook et.al.
> > >
> > > Sure edges still can have IPv4, but that's like edge having IPX or
> > > AppleTalk, it'll be highly local issue, no one expects to reach
> > > anywhere with it, and anticipates to translate 100% of external
> > > traffic.
> > >
> > > Amazon? Facebook? Google? Microsoft? Any appetite?
> > >
> > > --
> > >    ++ytti
> > > _______________________________________________
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> > >
>
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