Re: [v6ops] draft-ietf-6man-rfc4291bis prohibiting non-/64 subnets

--
Alexandre Petrescu
alexandre(_dot_)petrescu(_at_)cea(_dot_)fr, tél 0169089223

Le 24/02/2017 à 19:36, Alexandre Petrescu a écrit :
> Le 24/02/2017 à 19:21, Christopher Morrow a écrit :
> > On Fri, Feb 24, 2017 at 1:08 PM, Alexandre Petrescu
> > <alexandre(_dot_)petrescu(_at_)gmail(_dot_)com <mailto:alexandre(_dot_)petrescu(_at_)gmail(_dot_)com>> 
> > wrote:
> >
> >
> >     Le 24/02/2017 à 18:53, Christopher Morrow a écrit :
> >
> >
> >         yes, I think so.. for linux:
> >         $ sudo ip -6 addr add 2001:700:4::1 dev em1
> >
> >         gets me:
> >          inet6 2001:700:4::1/128 scope global
> >
> >
> >     That address is good, but how about the routing table?  Does it get
> >     an entry like 2001:700:4::/64?
> >
> >
> > $ ifconfig em1
> > <snip>
> >           inet6 addr: 2001:700:4::1/128 Scope:Global
> > <snip>
> >
> > and:
> > $ netstat -rnA inet6
> > Kernel IPv6 routing table
> > Destination                    Next Hop                   Flag Met Ref
> > Use If
> > 2001:700:4::1/128              ::                         U 256 0
> > 0 em1
> > <snip>
> > 2001:700:4::1/128              ::                         Un 0   1
> > 0 lo
> >
> > that sure seems like i only got what I paid for.. on:
> > $ uname -r
> > 3.13.0-92-generic
> Looks good in linux world.
>
> Alex
But, I would like to add that last time I checked (january 2015) the 
linux kernel complained in /var/log/messages  when receiving an RA 
containing a plen 65.  It called it "illegal" prefix length.
That RA was sent over usbnet.  There is no specification of 
IPv6-over-USB, there is no IID length requirement to be 64, because 
there is noo USB IEEE MAC address.
That was wrong at that time (call a 65 in RA "illegal"), I dont know 
whether it still the case.  I may check in some time in the following 
weeks, and this is the question I will follow: is the linux kernel 
complaining when receiving an RA with a plen 65 on usbnet?  If yes, then 
linux stilll has at least one problem with this 64.
What is sure is that there is still no IPv6-over-USB draft, so no IID 64 
on USB.
It's  a similar situation with cellular links instead of USB - no spec, 
but hidden assumptions about it being 64.  They are all wrong.
Alex

> >

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