Re: [DNSOP] I-D Action: draft-ietf-dnsop-svcb-https-01.txt

Mark Andrews <marka@isc.org> Tue, 14 July 2020 00:03 UTC

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Subject: Re: [DNSOP] I-D Action: draft-ietf-dnsop-svcb-https-01.txt
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Section 2.4.1.  AliasMode paragraph 2.  Why have "MUST NOT" here?                          

   The primary purpose of AliasMode is to allow aliasing at the zone
   apex, where CNAME is not allowed.  In AliasMode, TargetName MUST be
   the name of a domain that has SVCB, AAAA, or A records.  It MUST NOT
   be equal to the owner name, as this would cause a loop.

Nameservers and clients need to detect loops regardless of the number of
records that form the loop.  All this does is force vendors to write additional
code to detect this one sub-case of a loop.  These are also the only RR types
that need to have their owner names available to parse them.

Mark

-- 
Mark Andrews, ISC
1 Seymour St., Dundas Valley, NSW 2117, Australia
PHONE: +61 2 9871 4742              INTERNET: marka@isc.org