RE: A6 record status

[Sheng Jiang <[e-mail]>]

> > > In message <[e-mail]>, Brian E Carpenter writes:
> > > > On 2011-08-12 11:47, Mark Andrews wrote:
> > > > > I think it is make work
> > > >
> > > > That's why I am only suggesting an IESG decision, not a draft
> > > > and an RFC.
> > > >
> > > > > and won't change the amount of confusion.
> > > > > In addition A6 allows compresssion of the domain name in the
> rdata
> > > > > so it can't be treated as unknown (i.e. a opaque blob) by
> > > nameservers.
> > > >
> > > > If it's historic, servers shouldn't even contain any A6 records,
> > > > surely?
> > >
> > > Making something historic doesn't remove the old software or the
> > > old records.  Removing knowledge of A6 from recursive server will
> > > result in garbage A6 records being delivered to old clients that
> > > are A6 aware.  A6 aware clients still work as they ask for both
> > > AAAA and A6 records.
> >
> > Yes, your statement are right. However, the case of A6 is there are
> few curre
> > nt A6 software or records. As far as I know, there are no commercial
> A6 suppo
> > rts in the current global DNS system. A6 only existed in some
> experimental sy
> > stem, like 6net. So, what we are worried here is not these existing
> A6. By mo
> > ving A6 into historic, we are preventing any NEW A6 implementation or
> deploym
> > ent.
> >
> > Sheng
> 
> The root servers are getting 100's of A6 q/s (~20:1 AAAA:A6
> <http://k.root-servers.org/statistics/GLOBAL/daily/>).  There is
> still a very large base of A6 using software out there regardless
> of whether they are getting NODATA responses or not.

Oops... This looks different from many people's thought. However, this is a fact that shows A6 is actually in use. Based on this, moving A6 to historic is much more complex than an IESG decision. We may need more investigation on how these A6 records are current used. We also need to investigate what impact may have if A6 is abolish. Another important question is whether there are A6-only client. It looks a lot investigation and analysis work, which is definitely worth a draft, before we can make the decision to moving A6 into history or start a phase out plan.

Sheng
 
> I don't know what percentage of responses are NODATA and what have
> actual A6 records.  I do think we need to know answers to these sorts
> of questions.
> 
> Mark
> 
> > > One needs a phase out plan if you want to remove A6 support and it
> > > is likely to need to be decades long given how long people run old
> > > nameservers for.
> > >
> > > > > If one wants to do something about IPv6 addresses in the DNS
> add
> > > > > support for scoped addresses.  Link-local could then be useful.
> > > >
> > > > Different topic, and I suspect much more complex.
> > > >
> > > >    Brian
> > > --
> > > Mark Andrews, ISC
> > > 1 Seymour St., Dundas Valley, NSW 2117, Australia
> > > PHONE: [phone]                 INTERNET: [e-mail]
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> --
> Mark Andrews, ISC
> 1 Seymour St., Dundas Valley, NSW 2117, Australia
> PHONE: [phone]                 INTERNET: [e-mail]