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

[Benoit Claise <[e-mail]>]

Ignas,
> Hi Benoit,
>
> Thank you for reviewing.
>
> 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.
Thanks Ignas.
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.

Regards, B.
>
> The topics of 2 byte padding and any integer value in global 
> administrator field have been discussed in the WG.
>
> Ignas
>
>
>
> On 04/01/2017 14:52, Benoit Claise wrote:
>> Benoit Claise has entered the following ballot position for
>> draft-ietf-idr-large-community-11: Discuss
>>
>> When responding, please keep the subject line intact and reply to all
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>>
>>
>> Please refer to 
>> https://www.ietf.org/iesg/statement/discuss-criteria.html
>> for more information about IESG DISCUSS and COMMENT positions.
>>
>>
>> The document, along with other ballot positions, can be found here:
>> https://datatracker.ietf.org/doc/draft-ietf-idr-large-community/
>>
>>
>>
>> ----------------------------------------------------------------------
>> DISCUSS:
>> ----------------------------------------------------------------------
>>
>> I see from the abstract: "The attribute is suitable for use with
>> four-octet ASNs."
>> I also see this text, which doesn't mention four-octet ASNs
>>
>>     The Global Administrator field is intended to allow different
>>     Autonomous Systems to define BGP Large Communities without
>> collision.
>>     This field SHOULD be an Autonomous System Number (ASN), in which
>> case
>>     the Local Data Parts are to be interpreted as defined by the owner
>> of
>>     the ASN.  The use of Reserved ASNs (0 [RFC7607], 65535 and
>> 4294967295
>>     [RFC7300]) is NOT RECOMMENDED.
>>
>> What if the ASN is two bytes, we use padding? How?
>> Even if we would say: "This field SHOULD be an four-octet Autonomous
>> System Number (ASN)", it doesn't preclude inserting a two-octet ASN in
>> the Global Administrator field.
>> Isn't it better to specify how?
>>
>> >From RFC 6793:
>>
>>     Currently assigned two-octet AS numbers are converted into
>> four-octet
>>     AS numbers by setting the two high-order octets of the four-octet
>>     field to zero.  Such a four-octet AS number is said to be mappable
>> to
>>     a two-octet AS number.
>>
>>
>> ----------------------------------------------------------------------
>> COMMENT:
>> ----------------------------------------------------------------------
>>
>> Thanks John for an excellent shepherd writeup.
>>
>>
>
> .
>