BIND 10 #834: no EDNS0 on outgoing queries

[BIND 10 Development]

#834: no EDNS0 on outgoing queries
-------------------------------------+-------------------------------------
                   Reporter:  jelte  |                 Owner:  jelte
                       Type:         |                Status:  reviewing
  defect                             |             Milestone:
                   Priority:  major  |  Sprint-20110614
                  Component:         |            Resolution:
  resolver                           |             Sensitive:  0
                   Keywords:         |           Sub-Project:  DNS
            Defect Severity:         |  Estimated Difficulty:  1.0
  Medium                             |           Total Hours:  0
Feature Depending on Ticket:         |
        Add Hours to Ticket:  0      |
                  Internal?:  0      |
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Changes (by stephen):

 * owner:  stephen => jelte


Comment:

 Changes are OK so please merge.

 However, this adds the OPT RR to all upstream queries (except those where
 an incoming packet is passed upstream with minimal change).
 [http://tools.ietf.org/html/rfc2671#section-5.3 RFC 2671 Section 5.3]
 states:
 {{{
 5.3. Responders who do not understand these protocol extensions are
      expected to send a response with RCODE NOTIMPL, FORMERR, or
      SERVFAIL.  Therefore use of extensions should be "probed" such that
      a responder who isn't known to support them be allowed a retry with
      no extensions if it responds with such an RCODE.  If a responder's
      capability level is cached by a requestor, a new probe should be
      sent periodically to test for changes to responder capability.
 }}}
 This suggests that we need to add the ability to send message upstream
 with no EDNS0.  It also suggests that the NSAS needs to be extended to
 include a record of whether a nameserver has EDNS0 support.

-- 
Ticket URL: <http://bind10.isc.org/ticket/834#comment:13>
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