[AusNOG] IPv6 DNS Providers in Australia

[Mark Andrews]

In message <20120625222329.21168.qmail at f5-external.bushwire.net>, "Mark Delany"
 writes:
> > > Very interesting - admittedly, the first I've heard of it. Are you
> > > aware of any applications that rely on this?
> > 
> > Wrong question.  A better question would be what protocols didn't
> > use a new type because DNS control panels didn't support it.  SPF[1],
> > DKIM come to mind.
> 
> To be fair, pretty much every part of the infrastructure has been
> incapable of supporting unknown types for most of the life of DNS. And
> that mind-set was built into every operational component along with
> nearby participants such as firewalls that helpfully block unknown
> types.

Which just isn't true.  Recursive servers have pretty handled unknown
types from day dot.  They are just opaque blobs of data.  Stub
resolvers have handled unknown types from day dot.  It was authoritative
servers that had problems and only because you needed to be able
to load/save data.

And for the last decade most nameservers have handled unknown data.

DNSSEC aware servers have formally treated unknown types as opaque
blobs much longer.  They may not have been able to load the types
but they could validate answers they got from servers that could.

RFC 103[45] said to expect new types and new types have been
introduced though the entire history of the DNS.  The intent to
treat unknown types as opaque blobs is in RFC 103[45].

> Vendors that provided stub-caches like nscd and mDNSResponder along
> with a muddle of confusing and type-specific client libraries only
> made matters worse.

The original resolver libraries handled every possible type.
 
> So it wasn't just control panels, there are probably 5-6 components in
> the path of a query that did (or still do) need orchestrated fork-lift
> upgraded to support new types. Such a daunting undertaking explains
> why some of these TXT usurpers originally contemplated HTTP in
> preference to DNS.
> 
> 
> Mark.
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-- 
Mark Andrews, ISC
1 Seymour St., Dundas Valley, NSW 2117, Australia
PHONE: +61 2 9871 4742                 INTERNET: marka at isc.org