Re: IPv6 /64 links (was Re: ipv6 book recommendations?)

[Masataka Ohta <mohta () necom830 hpcl titech ac jp>]

Tony Hain wrote:

> Note the ~ ...  And ARP requires media level broadcast, which ND does not.

Any multicast capable link is broadcast capable.

> Not all media support broadcast.

A fundamental misunderstanding of people designed IPv6 is that
they believed ATM not broadcast capable but multicast capable.

> > As ND requires MLD and DAD, overhead in time when addresses are
> > assigned is very large (several seconds or more if multicast is not very
> > reliable), which is harmful especially for quicking moving mobile hosts.
>
> So leveraging broadcast is why just about every implementation does a
> gratuitous ARP-and-wait multiple times,

Not at all. IPv4 over something does not have to be ARP.

IPv6 is broken eventually requiring all link use ND, even
though ND was designed for stational hosts with only Ethernet,
PPP and ATM (with a lot of misunderstanding) in mind.

> MLD does not need to significantly increase time for address
> assignment.

That DAD latency is already too bad does not validate additional
latency of MLD.

> If hosts are moving quickly the fabric needs to be able to keep
> up with that anyway, so adding a new multicast member needs to be fast
> independent of IPv6 address assignment.

If only IPv6 over something were defined reflecting link
specific properties.

Instead, universal timing specification of ND and MLD ignoring
various links in the world makes it impossible to be fast.

> BS ... Broadcasts are dropped all the time,

On Ethernet, broadcast is as reliable as unicast.

> MLD snooping was a recent addition

MLD snooping ~= IGMP snooping.

> it is an efficiency issue some devices chose to assert that isn't strictly
> required for end-to-end operation.

There certainly are many problems, including but not limited
to efficiency ones, caused by ND ignoring the end to end
principle to make routers more intelligent than hosts, against
which MLD snooping cloud be a half solution.

But, so what?

> Just because you have never liked the design choices and tradeoffs made in
> developing IPv6 doesn't make them wrong.

It is the ignorance on the end to end principle which makes
IPv6 wrong.

> Continuing to complain about existing IPv6 design
> does nothing productive.

Insisting on broken IPv6 design does nothing productive.

> If there are constructive suggestions to make the
> outcome better, take them to the IETF just like all the
> constructive changes made to IPv4.

IPv6 is a proof that IETF has lost the power to make
the world better.

                                                Masataka Ohta