Bug #42810 for bind9-public: dns64 should exclude mapped v4 addresses by default.

We provide the mechanism (exclude) but don't populate exclude with a default of ::ffff:0.0.0.0/96. 5.1.4. Special Exclusion Set for AAAA Records Some IPv6 addresses are not actually usable by IPv6-only hosts. If they are returned to IPv6-only querying agents as AAAA records, therefore, the goal of decreasing the number of failure modes will not be attained. Examples include AAAA records with addresses in the ::ffff:0:0/96 network, and possibly (depending on the context) AAAA records with the site's Pref64::/n or the Well-Known Prefix (see below for more about the Well-Known Prefix). A DNS64 implementation SHOULD provide a mechanism to specify IPv6 prefix ranges to be treated as though the AAAA containing them were an empty answer. An implementation SHOULD include the ::ffff/96 network in that range by default. Failure to provide this facility will mean that clients querying the DNS64 function may not be able to communicate with hosts that would be reachable from a dual-stack host. -- Mark Andrews, ISC 1 Seymour St., Dundas Valley, NSW 2117, Australia PHONE: +61 2 9871 4742 INTERNET: marka@isc.org

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The CHANGES entry had misspellings which I was going to quickly fix: s/exlude/exclude/ s/a exclude/an exclude/ but after looking I was wondering two things: should the CHANGES entry mention RFC 6147 (section 5.1.4) for this change? and should notes.xml be updated? Is this a noticable behavior change? The docs changed: If not defined, <command>exclude</command> - defaults to none. + defaults to ::ffff:0.0.0.0/96. Also should another test be added for returning an address not matching the default exclude?

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