AAAA, A6, or both?

[Antonio Querubin]

On Fri, 18 Jan 2002, Chuck Yerkes wrote:

> Quoting Antonio Querubin (tony@lava.net):
> > On Fri, 18 Jan 2002, John Klos wrote:
> > > I am interested to know why you dismiss A6 out of hand with no
> > > information. Have you come across RFC 1886-only resolvers?
> >
> > Very few service providers have upgraded their production DNS to handle A6
> > so I suspect the vast majority of DNS currently in operation will still
> > barf on A6 RRs.  If I recall correctly, BIND 8.x and earlier, for example,
> > will reject an entire zone if it sees RRs it doesn't understand, so it's
> > not likely you'll see A6 become widespread until BIND 9.x is more widely
> > deployed on DNS operating as secondary nameservers.
>
>
> BIND 8.3 will not barf on A6 records. Not sure that it knows
> what to do with them, but it's supposed to now accept "unknown RRs".
>
> This is handy when I have zones that are secondaried by BIND 8 people.

That's good to know but the idea is that there are still many DNS running
pre-8.3 and pre-9.x BIND versions which will reject the entire zone if
they detect unknown RRs.  Until we see more DNS upgraded to recent
software versions there'll continue to exist a natural tendency to avoid
the use of A6 RRs in zone files.  That competes with the "if it aint broke
don't fix it" reluctance to upgrade software.  And then there are those
operators that never bother applying upgrades or patches and we all know
those are few in number ... NOT!