Re: [Idr] draft-chen-idr-ctr-availability-00.txt

Hi Robert,

    Thank you very much for your comments and suggestions.
    My answers/explanations are inline below with prefix [HC].

Best Regards,
Huaimo
________________________________
From: Idr <idr-bounces@ietf.org> on behalf of Robert Raszuk <robert@raszuk.net>
Sent: Monday, March 9, 2020 5:42 AM
To: idr@ietf. org <idr@ietf.org>
Subject: [Idr] draft-chen-idr-ctr-availability-00.txt

Dear Authors,

I read your draft and sorry to say do not have good news.

1)

First you break IBGP rule from base BGP spec. It is pretty standard that controllers distribute information via IBGP and with the help of RRs. Only RRs can send information received over IBGP to other IBGP peers.

In your case it is hard to assume that all NEs are RRs. It is also hard to assume that always multiple controllers from the same controller cluster will be connecting to the same RRs.

[HC]: It is not necessary to assume that all NEs are RRs. In general, it seems enough to assume that every edge NE is connected to the controller cluster, and one or two edges of the network are connected to multiple controllers in the cluster.

2)

The best solution to your problem is to have two independent controller clusters. When fatal intra-cluster failures occur all cluster members should drop BGP sessions to the network.

[HC]: Using two or more independent controller clusters for network or controller reliability/availability is another solution, which we will consider.

3)

Asking all network elements to participate in exchanging information between controllers is really not a good idea. Not to mention that your current encoding does not even have a notion of cluster id.

[HC]: In general, only one or two edges of the network will participate in exchanging information about controllers between controllers. We will consider cluster ID notion and encoding.

Many thx,
R.

---------- Forwarded message ---------
From: <internet-drafts@ietf.org<mailto:internet-drafts@ietf.org>>
Date: Mon, Mar 9, 2020 at 2:08 AM
Subject: I-D Action: draft-chen-idr-ctr-availability-00.txt
To: <i-d-announce@ietf.org<mailto:i-d-announce@ietf.org>>

A New Internet-Draft is available from the on-line Internet-Drafts directories.

        Title           : BGP for Network High Availability
        Authors         : Huaimo Chen
                          Yanhe Fan
                          Aijun Wang
                          Lei Liu
                          Xufeng Liu
        Filename        : draft-chen-idr-ctr-availability-00.txt
        Pages           : 12
        Date            : 2020-03-08

Abstract:
   This document describes protocol extensions to BGP for improving the
   reliability or availability of a network controlled by a controller
   cluster.

The IETF datatracker status page for this draft is:
https://datatracker.ietf.org/doc/draft-chen-idr-ctr-availability/<https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fdatatracker.ietf.org%2Fdoc%2Fdraft-chen-idr-ctr-availability%2F&data=02%7C01%7Chuaimo.chen%40futurewei.com%7C4afaa98d844947f1b03608d7c40e4481%7C0fee8ff2a3b240189c753a1d5591fedc%7C1%7C0%7C637193437868987310&sdata=lOGxdK%2BGukAtjt3W3AoBq3hxmt8vNBC1fAvpMv5ROyI%3D&reserved=0>

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