Subject: [DNSOP] Terminology: forwarding and forwarder

From: Paul Hoffman <[email-masked]>
Date: Fri, 24 Apr 2015 17:55:09 -0700

Greetings again. After the active discussion on these terms, we propose the following, which tries to hew closely to both RFCs. Comments are certainly welcome.

--Paul Hoffman

   Forwarding -- The process of one server sending a DNS query with the
   RD bit set to 1 to another server to resolve that query.  Forwarding
   is a function of a DNS resolver; it is different than simply blindly
   relaying queries.

   [RFC5625] does not give a specific definition for forwarding, but
   describes in detail what features a system that forwards need to
   support.  Systems that forward are sometimes called "DNS proxies",
   but that term has not yet been defined (even in [RFC5625]).

   Forwarder -- Section 1 of [RFC2308] describes a forwarder as "a
   nameserver used to resolve queries instead of directly using the
   authoritative nameserver chain".  [RFC2308] further says "The
   forwarder typically either has better access to the internet, or
   maintains a bigger cache which may be shared amongst many resolvers."
   That definition appears to suggest that forwarders normally only
   query authoritative servers.  In current use, however, forwarders
   often stand between stub resolvers and recursive servers.  [RFC2308]
   is silent on whether a forwarder is iterative-only or can be a full
   resolver.