Hi Robert,

> But this will hide BGP churn for a given NET to be detectable by BMP 
> receiver. Is this a good thing ?



The question is: how expensive is it to report everything bit-for-bit to the 
BMP collector?

If you want to report everything, you have to store everything.
Which will require bufferspace. How much? You don't know in advance. Might be a 
lot.



The current way of doing things allows the BMP implementation on a router to be 
pretty efficient.

When BGP receives routes, you store them in the BRIB. You don't store anything 
special for BMP (expect maybe timestamps, or other meta-data).

When BMP on a router is going to send BMP updates, it just walks the BRIB, and 
sees which NLRI/routes have not been sent to the collector yet.
BGP needs only 1 bit of information for that (to be precise: 1 bit per BMP 
session per NLRI/route).



If you want to see all churn, you need loads of buffers.
And BMP stops being an easy and efficient protocol.
So yeah, I am greatly in favor of allowing "compression" (aka skipping 
reporting outdated info).



henk.




> Op 21-09-2022 07:52 schreef Robert Raszuk <[email protected]>:
> 
> 
> 
> 
> 
> Hi Paolo,
> 
> 
> > A-la: there is multiple updates related to a certain NLRI by when a BMP
> > message is to be sent out, let's state-compress (ie. not send out) those
> > that were already obsoleted by a subsequent update.
> 
> 
> But this will hide BGP churn for a given NET to be detectable by BMP 
> receiver. Is this a good thing ? I am not sure. It is a loss of information 
> to me. 
> 
> 
> Thx,
> R. _______________________________________________
> GROW mailing list
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