Re: [Sidrops] draft-ietf-sidrops-8210bis flag bits

Randy Bush <randy@psg.com> Sat, 07 May 2022 19:13 UTC

Date: Sat, 07 May 2022 12:13:50 -0700
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From: Randy Bush <randy@psg.com>
To: Christopher Morrow <christopher.morrow@gmail.com>
Cc: SIDR Operations WG <sidrops@ietf.org>, Warren Kumari <warren@kumari.net>
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Subject: Re: [Sidrops] draft-ietf-sidrops-8210bis flag bits
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>> alternatively, we could have an ASPA4 and ASPA6.  parallel
>> construction is nice.  but the actual PDUs would be *identical*
>> except for the PDU Type.
>
> it seems, to me, that having the parallel pdus is ok. it might be nice
> to avoid 2x pdu types, but we (I think) certainly do not want to
> change how flag bits are defined suddenly.

the choice is not that extreme.  as the AFI flag bit is really only
needed for the new ASPA PDU, i suggested a second and separate flag
field, see AFI Flag below

>> 0          8          16         24        31
>> .-------------------------------------------.
>> | Protocol |   PDU    |                     |
>> | Version  |   Type   |        zero         |
>> |    2     |    11    |                     |
>> +-------------------------------------------+
>> |                                           |
>> |                 Length                    |
>> |                                           |
>> +-------------------------------------------+
>> |          |          |                     |
>> |  Flags   | AFI Flag |  Provider AS Count  |
>> |          |          |                     |
>> +-------------------------------------------+
>> |                                           |
>> |    Customer Autonomous System Number      |
>> |                                           |
>> +-------------------------------------------+
>> |                                           |
>> |    Provider Autonomous System Numbers     |
>> |                                           |
>> ~-------------------------------------------~

unless someone comes up with a better scheme, i will do this in the next
rev, after the IMC dreadline in a couple of weeks.  there were a lot of
good directorate reviews.

randy

[Sidrops] draft-ietf-sidrops-8210bis flag bits Randy Bush
Re: [Sidrops] draft-ietf-sidrops-8210bis flag bits Christopher Morrow
Re: [Sidrops] draft-ietf-sidrops-8210bis flag bits Randy Bush