Re: about violation of standards

[神明達哉 <[e-mail]>]

At Mon, 22 Apr 2019 18:37:08 +0200,
Yucel Guven <[e-mail]> wrote:

> > This logic doesn't make sense to me at all.  There was a very widely
used
> > implementation of commercial router (I don't name it as it's not my
> > purpose to pick a particular vendor) that forwarded an IPv6 packet
> > whose source address is link-local from one link to another link,
> > instead of returning an ICMPv6 destination unreachable error, code 2,
> > as specified in RFC4443.
>
> That is very interesting point indeed.
> Do you mean that billions of people's data, information, etc...etc... from
> their Link-locals
> can easily be routed to somewhere that no one knows? Just because of
> "that vendor" (or vendors?)

In theory yes, but I suspect it was quite unlikely in practice,
since when the source address is link-local, the destination address
is usually also link-local.  That implementation didn't let such
packets leak to a different link; this bug only happened when the
destination address was global.  I also don't know if this
implementation still has this bug today (note the past tense).

Anyway, such details are not the main point in this thread.  I just
gave a concrete example of why it doesn't make sense to justify a
broken behavior because of a "widely used implementation".  (hmm,
actually, these two cases have some common point that may matter in
the main context: in both cases the underlying implementation is
"widely used", but the usage of the broken behavior should be pretty
rare).

> Anyways, my concern is about huge amount of addresses of the fe80::/10.
> There are 281,474,976,710,655 =  281 Trillion 474 Billion 976 million 710
> Thousand 655 addresses
> in between  fe80:0:0:0::/64  and fe80:ffff:ffff:ffff::/64.
> If we just take  fe80:1::/32 or /64, then it breaks RFC4291 due to 54
zeros..
>
> Is it right time to modify RFC4291?

I don't think it's my call, but I provided some view of mine on a
related point in a separate thread:
https://mailarchive.ietf.org/arch/msg/ipv6/nRuLvdZptV2aR3TTzvh0WCKo7fQ
https://mailarchive.ietf.org/arch/msg/ipv6/D4YaezwdzKJ31mhKiqa8J8UWhoU

I don't know if it's the "right time", but I don't refuse an attempt
of updating RFC4291 on this point outright.  In my understanding many
of the participants in the recent relevant threads were also open to
listen to such attempts; they just rightly requested a valid
justification, and they simply didn't see it (neither did I, btw).

--
JINMEI, Tatuya