Sorry too late to comment, The word "Caching DNS Servers" and "Caching servers" are not defined by DNS RFCs. They should be "full-service resolvers" defined by RFC 1123.
# Some authoritative DNS server software have packet cache or hot spot # cache. They may be "caching DNS servers". -- Kazunori Fujiwara, JPRS <fujiw...@jprs.co.jp> _______________________________________________ DNSOP mailing list DNSOP@ietf.org https://www.ietf.org/mailman/listinfo/dnsop