Re: [DNSOP] abandoning ANAME and standardizing CNAME at apex

Ondřej Surý <ondrej@isc.org> Tue, 19 June 2018 20:33 UTC

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Date: Tue, 19 Jun 2018 22:33:06 +0200
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Subject: Re: [DNSOP] abandoning ANAME and standardizing CNAME at apex
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Oh, what about this?

https://tools.ietf.org/html/draft-sury-dnsext-cname-dname-00

:-)

O.
--
Ondřej Surý
ondrej@isc.org

> On 19 Jun 2018, at 15:18, Petr Špaček <petr.spacek@nic.cz>; wrote:
> 
> Hello dnsop,
> 
> beware, material in this e-mail might cause your head to explode :-)
> 
> This proposal is based on following observations:
> - It seems that DNS protocol police lost battle about CNAME at apex,
>  is is deployed on the Internet.
> - Major DNS resolvers like BIND, Unbound, PowerDNS Recursor, dnsmasq
>  already have code to cope with the "impossible" case of CNAME at the
>  apex and deal with it in ways which do not break stuff on resolver
>  side.
> - Authoritative servers of vendors named above refuse to serve CNAME at
>  apex.
> - There are CDNs etc. which allow users to create CNAME at apex
>  no matter what the standards and "normal" servers say and do.
> (We have found out this because Knot Resolver is missing hacks for CNAME
> at apex and users complain that "it works with every other resolver".)
> 
> 
> Take a deep breath!
> 
> 
> Given that resolver side somehow works already ...
> could we standardize this obvious violation of RFC 1035?
> 
> It is very clear violation of the standard, but almost everyone found
> his way around it using different hacks. These hacks are not going away
> because all the CDNs just don't care about standards so we will have
> to maintain this code no matter what a great solution we will invent for future. I.e. adding ANAME will just increase complexity because CNAME at apex will be there for a long time (if not forever).
> 
> I personally do not like this but it seems better to think though
> corner cases in code we already have in production (i.e. think through current hacks for CNAME at apex) instead of inventing new things like ANAME (or whatever else).
> 
> Opinions? Tomatoes? Can it work? If not, why not?
> 
> -- 
> Petr Špacek  @  CZ.NIC
> 
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