Re: [Idr] Benoit Claise's Discuss on draft-ietf-idr-large-community-11: (with DISCUSS and COMMENT)

Benoit Claise <> Wed, 04 January 2017 18:43 UTC

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To: Job Snijders <>
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From: Benoit Claise <>
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Date: Wed, 04 Jan 2017 19:43:23 +0100
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Subject: Re: [Idr] Benoit Claise's Discuss on draft-ietf-idr-large-community-11: (with DISCUSS and COMMENT)
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Hi Job,

So basically, you're telling me: "The attribute is suitable for use with 
ASNs.", right?
Is this what needs to be in the abstract?

Regards, B.
> Hi Benoit,
> On Wed, Jan 04, 2017 at 04:39:25PM +0100, Benoit Claise wrote:
>>> Global Administrator field is a 4 octet integer that is used to carry AS
>>> number but it is not mandatory to interpret it as an AS number only
>>> (while a typical use case is for carrying AS number) - two peers can
>>> agree on any value that has meaning between those peers. Representation
>>> on the wire is in network byte order, and 2 byte AS number will get
>>> naturally padded with two zero bytes in front. Virtually all deployments
>>> today are AS4 capable and use AS4 encoding even for AS number values
>>> that fit into 16 bit value range therefore AS number is a 4 octet entity
>>> already.
>> Then this sentence in the abstract "The attribute is suitable for use
>> with four-octet ASNs." is misleading, right? At least to me. The
>> attribute is suitable for four-octets ASNs and two-octets ASNs encoded
>> in four-octets. This would be more in line with "This field SHOULD be
>> an Autonomous System Number (ASN)" later on.
> I am under the impression that nowadays the IETF community considers all
> ASNs to be four-octet ASNs, however, some of those ASNs can be encoded
> as a two octet value. The Large Communities specification is suitable
> for usage in Autonomous Systems from all walks of life, where as rfc1997
> communities are unsuitable for all ASNs, specifically those ASNs which
> cannot be encoded as two-octet values.
> Kind regards,
> Job
> .