Re: Message Numbers and Disconnect Codes - Local Use

[Chris Lonvick <clonvick%cisco.com@localhost>]

Hi,

On Fri, 24 Sep 2004, [iso-8859-1] Niels Möller wrote:

> Henrick Hellström <henrick%streamsec.se@localhost> writes:
>
> > Niels Möller wrote:
> > > I think, quite strongly, that such substructure should be out of scope
> > > for the core drafts.
> >
> > Fair enough, but I suggest that there at least should be stipulated in
> > the specification that locally assigned disconnect codes MUST NOT be
> > sent by standard protocol features.
>
> Right, locally defined numbers should not appear on the wire unless
> you have somehow agreed with the receiver what they should mean.
>
> One example where that can be used safely on the wire, is if you
> receive a CHANNEL_OPEN request for some locally defined channel type
> "foo-channel%lysator.liu.se@localhost", then you can safely reply with a
> CHANNEL_OPEN_FAILURE and any locally defined reason code associated
> with the specification for that channel type.
>
> > The appropriate way to avoid such situations ought to be to stipulate
> > that locally assigned disconnect codes must only be sent by locally
> > specified protocol features (e.g. keyestablishment@host,
> > subsystem@host etc).
>
> That is sane advice. But it is also an important part of the idea of
> the locally assigned numbers, that you are allowed to use these
> numbers in anyway you please, as long as you know what you're doing,
> and don't expect interoperability with other standards compliant
> implementations.
>
> The easiest way to sum this up is to say that use of locally defined
> numbers is *not* standardized in any way, that they can be used only
> under prior agreement between the involved ssh installations, and that
> any agreements on how they are to be used are out of scope for the
> specification. Is there some standard phraseology for this? It's
> surely not unique for ssh.
>
> Regards,
> /Niels


I can specify the term "Private Use" from RFC 2434:

   Private Use - For private or local use only, with the type and
           purpose defined by the local site. No attempt is made to
           prevent multiple sites from using the same value in different
           (and incompatible) ways. There is no need for IANA to review
           such assignments and assignments are not generally useful for
           interoperability.

           Examples: Site-specific options in DHCP [DHCP] have
           significance only within a single site.  "X-foo:" header
           lines in email messages.


If this is OK with everyone, I can make global changes to the documents to
reflect that the use of the term "local use" is consistent with this
definition from 2434.

Thanks,
Chris