recursion and forwarding

[Phil Mayers]

On 01/12/2012 06:15 PM, Adamiec, Lawrence wrote:

> So when does recursion occur, before the query is forwarded or never? I
> thought recursion was supposed to go looking for the answers. If
> recursion does not return an answer then does the query get forwarded?

"forwarders" IIRC works as follows:

  1. If query answer in cache, reply from cache to client, stop
  2. Send query to forwarders
  3. If reply, add to cache, reply to client, stop
  4. No reply: if "forward only" set, error to client, stop
  5. Perform normal recursion

That is - it tries cache, then the forwarders, then does recursion 
itself (unless "forward only" is set).