Hi, draft-hoffman-dns-terminology-02 has the following definition:
Passive DNS -- A mechanism to collect large amounts of DNS data by storing queries and responses from many recursive resolvers. Passive DNS databases can be used to answer historical questions about DNS zones such as which records were available for them at what times in the past. I think this is referring to the concept originally described in Florian Weimer's "Passive DNS Replication" paper [0], which sort of combines the collection and retention aspects into a single term. Also, scale ("large", "many") may be an interesting property of a particular deployment, but it isn't really intrinsic to the definition of the term. Nor do all systems collect both queries and responses (some only collect responses). I would propose something like the following instead: Passive DNS Replication -- A mechanism to collect and store resource records by observing responses, usually those sent by authoritative servers. Passive DNS databases can be used to recover DNS records which were served in the past, and may allow certain kinds of "inverse" searches of the stored records. Sometimes shortened to "passive DNS". [0] http://www.enyo.de/fw/software/dnslogger/first2005-paper.pdf -- Robert Edmonds _______________________________________________ DNSOP mailing list DNSOP@ietf.org https://www.ietf.org/mailman/listinfo/dnsop