[DNSOP] CDS Bootstrapping for vanity DNS servers

rubensk@nic.br Wed, 22 June 2022 02:51 UTC

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Subject: [DNSOP] CDS Bootstrapping for vanity DNS servers
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During a meeting today of ROW (https://regiops.net), the I-D on CDS bootstrapping by using a DNSSEC-signed name at name server zone (https://datatracker.ietf.org/doc/draft-ietf-dnsop-dnssec-bootstrapping/) was discussed.
In that discussion, it was mentioned that the current draft only supports out-of-bailiwick name servers; I replied that the same principle could be applied to in-bailiwick name server by usage of the reverse DNS zones for IPv4 and IPv6.

Reverse DNS zones have been signed for a while now, as you can see in this walk-thru of the DNSSEC trust chain for one IP address:

So, instead of _dsboot.example.com.br._signal.ns1.example.net.br, it could be a CDS/CDNSKEY record at _dsboot.example.com.br._signal. or  _dsboot.example.com.br._signal.b.a. Or put _dsboot.example.com.br as the PTR response for that query, but keeping it aligned with direct resolution seems preferable to me.

Whether this violates any currently in-force DNS RFCs/STDs requirement, or if would fail or not to work with the current codebase of authority and recursive servers, I don't know.