Re: [Idr] WG Adoption call for draft-wang-idr-rd-orf-05.txt (2/4/2021 to 2/18/2021)

["Jakob Heitz (jheitz)" <[e-mail]>]

You are trying to have a VRF that is receiving routes to notify a VRF that is sending routes that it is sending too many routes.
The receiving VRF and the sending VRF are separated by several or many intermediate BGP speakers.
Bouncing ORFs back through these intermediate speakers is not a reliable way to achieve this notification.
This is because each intermediate speaker has multiple downstream speakers.
One speaker needs to receive the ORF from all of its downstream speakers before it can bounce the ORF upstream.
Thus, it's unlikely that the ORF will make it all the way to the source of the routes.
You are asking for something like a reverse BGP.
That can't scale.
The way that we find out whether a far away speaker got our route correctly is with looking glasses.
Looking glasses aren't implemented by BGP, because BGP operators don't want to store that kind of information.

Regards,
Jakob.

From: Aijun Wang <[e-mail]>
Sent: Thursday, February 11, 2021 8:12 AM
To: Robert Raszuk <[e-mail]>
Cc: Jakob Heitz (jheitz) <[e-mail]>; Susan Hares <[e-mail]>; [e-mail]; Acee Lindem (acee) <[e-mail]>
Subject: Re: [Idr] WG Adoption call for draft-wang-idr-rd-orf-05.txt (2/4/2021 to 2/18/2021)

Hi, Robert:
Aijun Wang
China Telecom


On Feb 11, 2021, at 23:40, Robert Raszuk <[e-mail]<mailto:[e-mail]>> wrote:


Now if all of the above is not done or done with mistakes and you indeed experience to many routes to be handled by data plane you stop locally importing those routes to local VRFs by VRF shutdown. The good thing here is that this will be noticed by all attached customers as their dynamic routing will propagate withdraws.
[WAJ] The BGP session is shared by several VPNs and cannot be shutdown in such situations. Procedures that you expect would not happen.


Where did I say to shutdown BGP session ?

I said VRF shutdown ... nothing to do with BGP sessions shutdown.

[WAJ] Don’t you think VRF shutdown has the more broader influences? RD-ORF influences only the newly advertised VPN routes. VRF shutdown will influence the existing VPN routes and its existing forwarding traffic.


- - -

Let me provide the analogy here ...

You are presenting a solution on what to do when we fly low and start hitting the top of the trees.

WG tells you that flying low is bad practice and should not take place providing what to do to mitigate it well - in the analogy train your ground crew not to overload the plane.

You say - Oh well we have different idea instead - when we throw away during the flight some passengers we can keep flying (on the edge of safety).
[WAJ] Just deny the onboard of new passengers, not throwing the existing passengers.


That's here we are with this.

- - -

Quite honestly when we started to deploy 2547 back in nearly 2000s we were preparing much more user friendly solution (a flavor of CSC - not CSC as defined in the RFC) where SP network would only deal with next hops and never with customer routes ... yet customer would have the same type of service. Quite honestly we have had even OSPF reflector ready for it. Problem was that at that time SPs said oh we want to take millions of customer routes - no problem. We just buy bigger RRs and bigger routers. So you can guess what happened with such idea - got shelved as if deployed would result in revenue loss :).

[WAJ] RD-ORF mechanism can encourage the provider to deploy inter-as VPN solutions because it gives them the granular control over the VPN routes propagation between ASBRs or RRs, which can certainly broader the VPN service coverage and the revenue.


Best,
R.