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

I am wondering – according to RFC 4271, how can an OPEN message ever exceed 284 bytes?
The bgp message header has 19 bytes and the OPEN message payload adds 10. This is 29, then the only 
addition here are the Optional Parameters which cannot exceed 255 bytes combined due to the 1 byte length field.

Therefore, an open message cannot exceed 284 bytes and if larger than 284 bytes, wouldn’t it be invalid. 

In this regard, I don’t really understand the whole discussion about allowing an OPEN message larger than 4K. 
It shouldn’t even be larger than 284 bytes?  Maybe I am missing something.

BTW, same is true for KEEPALIVE (max 19 bytes)

Oliver

On 3/7/17, 1:45 PM, "Idr on behalf of Enke Chen" <idr-bounces@ietf.org on behalf of enkechen@cisco.com> wrote:

    Hi, Folks:

    o There is no extra work for a receiver to cover message types other than UPDATE.
    o There is a little bit work for a sender that wishes to send a large OPEN (e.g.,
      using the prior capability and possibly subsequent NOTIFICATION).

    Additionally, I do not see a need to touch on the FSM specified in RFC 4271 even
    in the case of sending a large OPEN, which potentially may involve two separate
    consecutive sessions but each session would just follow the existing FSM.

    Thanks.   -- Enke

    On 3/7/17 7:32 AM, Susan Hares wrote:
    > Robert:
    > 
    > <individual contributor’s hat on>
    > 
    > Yep  - Easier to just include all messages.  
    > 
    >  
    > 
    > Sue
    > 
    >  
    > 
    > *From:*rraszuk@gmail.com [mailto:rraszuk@gmail.com] *On Behalf Of *Robert Raszuk
    > *Sent:* Tuesday, March 7, 2017 10:33 AM
    > *To:* Susan Hares
    > *Cc:* Randy Bush; Enke Chen; Jeffrey Haas; Alvaro Retana (aretana); idr-chairs@ietf.org; draft-ietf-idr-bgp-extended-messages@ietf.org; idr wg
    > *Subject:* Re: [Idr] AD Review of draft-ietf-idr-bgp-extended-messages-20
    > 
    >  
    > 
    > Hi Sue,
    > 
    >  
    > 
    >> My suggestion is to include all messages including future messages if approved.  
    > 
    >  
    > 
    > Ahh then it is great - we are in sync ! 
    > 
    >  
    > 
    > My other comments were just an opinion ... but if it is easier to extend all messages then perfect. 
    > 
    >  
    > 
    > Cheers,
    > 
    > R.
    > 
    >  
    > 
    >  
    > 

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