Re: Deprecating IPv6 (Re: draft-bourbaki-6man-classless-ipv6-00)

[Lorenzo Colitti <[e-mail]>]

What he said.

On Jun 3, 2017 12:23, "Mark Smith" <[e-mail]> wrote:

> On 3 June 2017 at 00:56, Job Snijders <[e-mail]> wrote:
> > Dear Lorenzo,
> >
> <snip>
> >
> >> Please stop trying to make IPv6 be the same as IPv4. That will take
> >> away our ability to make the Internet better once IPv4 is gone.
> >
> > I believe there to be tangible merit in making IPv6 feel and look more
> > like IPv4. Perhaps this becomes more apparent when one shifts the
> > innovation focus from layer-3 to higher layers.
> >
> > Making IPv6 look more like IPv4 (for instance through broader adoption
> > of DHCPv6 w/ routing options, and classlessness like in IPv4) will
> > positively impact IPv6 deployment.
> >
>
> I think that's the fundamental agenda here, although perhaps not
> realised. It is to devolve IPv6's capabilities and features to the
> point where IPv6 isn't really much more than IPv4 with a different
> packet format, and so the IPv4 operational practices people are
> comfortable with can be directly applied to IPv6 without change. This
> is because of the common human trait of intolerance of or resistance
> to change.
>
> If this proposal is accepted, then I think /120s will become the
> defacto subnet size, despite what the draft says about /64s being the
> recommended default. Here's the clue for why - RFC1918 addressed
> networks I've seen, where IPv4 address space doesn't need to be
> conserved (i.e., unlike public IPv4 address space), always use /24s as
> the defacto subnet size. "Same-same" is easier for us humans than
> "Same-different."
>
> Why do I have a different perspective? My first networking protocol
> was a more modern one than IPv4, Novell's IPX, derived from Xerox's
> XNS. Learning and operating IPv4 networks after operating IPX networks
> was a backwards step. The only major advantage that IPv4 provided over
> protocols designed in the 1980s and 1990s, such as IPX, Appletalk and
> CLNS, was that it provided organisations with Internet connectivity.
> On many other criteria, IPv4 was far inferior - entirely
> understandable, because it was fundamentally designed in the 1970s,
> and then adapted over time to cope with being used to build a global
> Internet work. It was never intended to be used to build a global
> internetwork connecting billions of devices -
>
> https://mailman.nanog.org/pipermail/nanog/2010-April/020488.html
>
> IPv6 is actually the first true protocol designed to suit the global
> "Internet" problem.
>
> I have a few horrible stories of seeing IPv4 routers with 4 x /24s or
> 25 x /26s on the same interface because renumbering and changing
> subnet masks of hosts into a single large enough subnet was more far
> expensive than sub-optimal forwarding across the same link. An
> impossible problem to have when the default subnet address space size
> far exceeds the practical link-layer node attachment limits (and in
> some cases impractical link-layer limits because of link layer
> "excessive" addressing - does an Ethernet really need 48 bit MAC
> addresses? Who's going to go close to attaching 2^46 nodes to one of
> them? The ND cache resource exhaustion type of problem also exists at
> layer 2 with switch tables ...)
>
> I don't want to experience or see people experience those sorts of
> IPv4 "right-sizing subnet" types of problems in IPv6.
>
> Regards,
> Mark.
>