new version of the reachability & exploration protocol

[Jari Arkko <jari.arkko@piuha.net>]

A revision of this draft has been submitted and is for
the moment accessible at

  
http://www.arkko.com/publications/shim6/draft-ietf-shim6-failure-detection-02.pdf
  (A .txt version exists as well but does not contain the state machine.)

This version of the draft contains a protocol for both
verifying reachability (FBD) and exploring for a working
pair, all part of an integrated solution that is quite
efficient in many respects. The protocol is intentionally
written in a standalone fashion to allow for potential
usage elsewhere (e.g. HIP).

There are some remaining issues that I did not find
solutions for before the deadline; these are pointed to
in the document at the relevant section.

Comments and suggestions appreciated, as always.

--Jari