Re: [Idr] WG adoption of draft-heitz-idr-large-community; one week to comment on early code point allocation

[Job Snijders <[e-mail]>]

On Mon, Sep 26, 2016 at 07:31:57PM -0400, Jeffrey Haas wrote:
> > On Sep 26, 2016, at 7:23 PM, Brian Dickson <[e-mail]> wrote:
> > 
> > RFC 1997 does not specifically say so, but definitely derives its
> > "special" from the ASN registry "special" for 0 and 65535.
> 
> Given the practice of encoding an AS number in the first portion of
> the community, reserving 0 made some amount of sense.
> 
> There also tends to be common practice to try to reserve 0 out of
> things resembling code points to have as the "uninitialized value".
> I'd recommend that practice continue for pretty much everything,
> including large comms.
> 
> > I think parity with 1997 would be the best course of action, and to
> > include-by-reference 32-bit values that are 16 bits of 0, followed
> > by 16 bits of 1997 values that are reserved, as well as the RFC 7300
> > 32-bit Reserved ASN.
> > I.e. 0:xxxx:yyyy, 65535:xxxx:yyyy, and 4294967295:xxxx:yyyy.
> 
> FWIW, I think things with "well known" semantics should stick to the
> reserved code point space in 1997 communities unless there's some
> motivation to have a common parameter/argument in it.  In that case,
> it fits the case for large comms anyway.

I agree with you Jeff. 

How about the following:

"""
    The Large Community attribute values in the following ranges are
    reserved:

             0:0:0 -          0:4294967295:4294967295
    4294967295:0:0 - 4294967295:4294967295:4294967295

"""

This way the lowest and highest possible value are reserved, and at some
later point (part of) these reserved ranges could be converted to
Well-known or something else if that need arises.

Going back to my earlier question, reserving 65535:*:*, just because it
was a meaningful value in rfc1997, does not make a whole lot of sense.
65535 was picked in rfc1997 because it was the highest value, we can
apply the same logic with Large.

Note: i propose just to reserve these two ranges, I don't see an
immediate need to open a registry given that we already have rfc1997
WKC.

Kind regards,

Job