Re: [Idr] AD Review of draft-ietf-idr-bgp-extended-messages-20

Jeffrey Haas <jhaas@pfrc.org> Wed, 08 March 2017 21:36 UTC

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From: Jeffrey Haas <jhaas@pfrc.org>
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Date: Wed, 8 Mar 2017 13:36:47 -0800
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To: "Alvaro Retana (aretana)" <aretana@cisco.com>
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Cc: "idr-chairs@ietf.org" <idr-chairs@ietf.org>, "draft-ietf-idr-bgp-extended-messages@ietf.org" <draft-ietf-idr-bgp-extended-messages@ietf.org>, Susan Hares <shares@ndzh.com>, "idr@ietf.org" <idr@ietf.org>
Subject: Re: [Idr] AD Review of draft-ietf-idr-bgp-extended-messages-20
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> On Mar 7, 2017, at 2:07 PM, Alvaro Retana (aretana) <aretana@cisco.com>; wrote:
> 
>> I'm not sure such guidance belongs in this document.  We already have
>> scenarios wherein normal protocol machinery can result in messages that are
>> too large.  The expected behavior is "treat as withdraw" to the next
>> downstream, similar to the BGP Error handling RFC.
>> 
>> Examples of this include AS_PATH or CLUSTER_LIST attributes needing to add a
>> new entry on a full PDU.
> 
> Ok…but is that documented anywhere?  I may be missing it, but I couldn’t find anything like that in rfc4271 or rfc7606.


At best, this is "reading between the lines".

If you can't form a valid PDU to encode in your Adj-rib-out, you withdraw your entry from the adj-rib-out.  This means you send an explicit withdraw.

I think it'd be gross to take this specific document and try to force it to be a normative clarification to this point.



-- Jeff