Re: [Idr] Review Request for draft BGP Overload

[amit bhagat <[e-mail]>]

Hi Robert,

Many thanks for your comments.

Initially, I thought about using a community but that would mean putting
all NLRIs in the Update message. This could also mean a different Update
per-neighbor/per-peergroup.

re: G-shut community - Reading through G-shut draft, it seems to be
targeting a single use case - maintenance. Additionally, it requires manual
configuration of route-policies. The way I envision this is a simple Update
that is applicable to all peers; no need to worry about manipulating any
BGP attributes.

re: new SAFI - The reason for requesting a new SAFI is so that a new NLRI
encoding can be defined to keep it simple. The existing SAFI would require
adding NLRIs to the Update message.

re: BGP session distinction - Is there a need to identify IBGP or EBGP
session? Perhaps I am missing something.

re: Global mode - the use case would be if a BGP speaker has multiple links
to different peers and running different AFI/SAFI pairs per links, it might
be just easy to drain a particular type of traffic rather than ALL traffic.

Additionally, one of the other use cases I am thinking of is when a BGP
speaker drops its Established neighbor-count below a threshold, it can
advertise itself as "Overloaded". This can help avoid congestion. Agreed,
this can also be the cause of network outage, but within a CLOS fabric, it
should not be a problem due to multiple paths.

Again, thanks for reviewing.

Amit.

On Tue, Jul 5, 2016 at 12:39 PM, Robert Raszuk <[e-mail]> wrote:

> Hi Amit,
>
> In an essence it seems that your proposal is just a subset of "Graceful
> BGP session shutdown"
> https://tools.ietf.org/html/draft-ietf-grow-bgp-gshut-06.
>
> Can you clarify how your encoding is any better then proposed by Pierre's,
> et al. G-Shut community?
>
> Why do you need a new SAFI for it ? Would it be easier to use community or
> attribute and send it over existing SAFIs ?
>
> How in your encoding one can distinguish IBGP sessions from EBGP sessions
> (case of core or edge line card replacement) ?
>
> What is the use case to not use "global" mode .. ie. when do you envision
> need to signal overload for only subset of AFI/SAFIs carried by given BGP
> speaker ?
>
> Many Thx,
> Robert.
>
>
> On Tue, Jul 5, 2016 at 9:25 PM, amit bhagat <[e-mail]> wrote:
>
>> Hey All,
>>
>> We are looking for your comments on the new draft
>> https://datatracker.ietf.org/doc/draft-bhagat-bgp-overload/
>>
>> We would really appreciate any comments and questions about the document.
>>
>> Best Regards,
>>
>> Amit Bhagat
>>
>>
>>
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>