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Re: Call for action vs. lost opportunity (Was: Re: Renumbering)

Subject: Re: Call for action vs. lost opportunity Was: Re: Renumbering
From: Noel Chiappa
Date: Fri, 14 Sep 2007 18:01:07 -0400 EDT
    > From: Greg Skinner <gds@xxxxxxxx>

    > It seemed like a reasonable thing to do to treat something like a net
    > or host unreachable as a transient condition ...
    > However, this practice doesn't seem to have made it into the
    > application-writing community at large, because lots of applications
    > fail for just this reason.

Then they are violating an explicit MUST in RFC-1122 ("Requirements for
Internet Hosts -- Communication Layers", October 1989), which says:  Destination Unreachable

  A Destination Unreachable message that is received with code 0 (Net), 1
  (Host), or 5 (Bad Source Route) may result from a routing transient and
  MUST therefore be interpreted as only a hint, not proof, that the specified
  destination is unreachable

This problem (people interpreting Unreachables as hard errors) was a problem
back then, 20 years ago, which is why we put that text in the RFC.

    > I wonder if even writing a BCP about this even makes sense at this
    > point, because the application writers (or authors of the references
    > the application writers use) may never see the draft, or even be
    > concerned that it's something they should check for.

I agree that it may be a waste of time, because they are *already* disobeying
an explicit requirements RFC.


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