On 4/25/19 8:34 PM, 神明達哉 wrote: > At Wed, 24 Apr 2019 11:44:37 +0200, > Matthijs Mekking <[email protected] > <mailto:[email protected]>> wrote: > >> I would like to start separate threads on the remaining issues of the >> ANAME draft. One issue that remains to be solved is whether having an A >> or AAAA record next to the ANAME should take precedence or not. >> >> Draft: https://datatracker.ietf.org/doc/draft-ietf-dnsop-aname/ >> Issue: https://github.com/each/draft-aname/issues/58 > [...] >> Jan Včelák mentioned that at least NS1 uses a different order of >> priority: If an sibling address record exists next to the ANAME it takes >> precedence and no target lookup is done for that address record type. > > Is this choice #2 of the github issue #58?
Correct. >>> sibling address records take precedence, don't to a target lookup for > an address type next to the ANAME. > > I'm not sure what this means...if this approach is taken and an > authoritative server has these for an example.com <http://example.com> zone: > > a.example.com <http://a.example.com>. ANAME another.example.org > <http://another.example.org>. > a.example.com <http://a.example.com>. AAAA 2001:db8::1 > > then, does it always just return the AAAA RRset to a query for > a.example.com/AAAA <http://a.example.com/AAAA>, regardless of any > possible changes to > another.example.org/AAAA <http://another.example.org/AAAA>? That is exactly what choice #2 does. But it can do a target lookup for the A RRset. > How is that AAAA created in the first place? (Is it taken from > another.example.org/AAAA <http://another.example.org/AAAA> or completely > up to the example.com <http://example.com> > maintainer?).. The AAAA record may initially be added to the example.com zone by the zone operator. With choice #2 it is not updated by the ANAME (with choice #1 it is). > Also, especially if both AAAA and A sibling records are available, > what's the purpose of ANAME in the first place if it's (effectively) > not used? > > I'm sure I'm just confused and don't understand the expected usage, > but I can't figure it out from the available descriptions. Could you > clarify it? Personally I agree that the purpose of ANAME becomes less useful with choice #2. The difference is that you can set up ANAME for example for AAAA only, or for A only. I don't know what the expected usage of that is, and that is why I am asking on the list. If it turns out there is no useful case, I think we should put text in the draft that says ANAME takes precedence over sibling A and AAAA records. Best regards, Matthijs > > -- > JINMEI, Tatuya > > _______________________________________________ > DNSOP mailing list > [email protected] > https://www.ietf.org/mailman/listinfo/dnsop > _______________________________________________ DNSOP mailing list [email protected] https://www.ietf.org/mailman/listinfo/dnsop
