[GROW] review of draft-ietf-grow-bmp-local-rib-07 (preparing for sheperd write-up)

Job Snijders <job@ntt.net> Tue, 03 November 2020 06:13 UTC

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Date: Tue, 03 Nov 2020 06:13:27 +0000
From: Job Snijders <job@ntt.net>
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Subject: [GROW] review of draft-ietf-grow-bmp-local-rib-07 (preparing for sheperd write-up)
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Dear group, authors

As part of the sheperd write-up I am reviewing the
draft-ietf-grow-bmp-local-rib-07 Internet-Draft. Overall the document
looks good to me.

Please consider these notes as input from an individual working group
participant. The suggestions are editorial in nature, my focus on
readability and clarity.

Thank you for your consideration!

Kind regards,

Job

### note 1

Suggested rewording of Abstract:

NEW Abstract:
The BGP Monitoring Protocol (BMP) defines access to various Routing
Information Bases (RIBs). This document updates BMP (RFC 8671) by
adding access to the Local Routing Information Base (Loc-RIB), as
defined in RFC 4271. The Loc-RIB contains the routes that have been
selected by the local BGP speaker's Decision Process. 

### note 2

Throughout the document I would suggest changing the phrase
"Local-RIB" to "Loc-RIB".

### note 3

Perhaps the first sentence of the introduction reads better if changed
to the following:

NEW:
	This document defines a mechanism to monitor the BGP Loc-RIB state
	of remote BGP instances without the need to establish BGP peering
	sessions.

### note 4

I have trouble understanding the following:

	The BGP Monitoring Protocol (BMP) suggests that locally originated
	routes are locally sourced routes, such as redistributed or otherwise
	added routes to the BGP instance by the local router. It does not
	specify routes that are in the BGP instance Loc-RIB, such as routes
	after best-path selection.

### note 5

OLD:
Adj-RIBs-In Post-Policy may still contain hundreds of thousands of
routes per-peer but only a handful are selected and installed in
the Loc-RIB as part of the best-path selection.

NEW:
The Adj-RIB-In for a given peer Post-Policy may contain hundreds of
thousands of routes, with only a handful of routes selected and installed
in the Loc-RIB after best-path selection.

### note 6

Section 1.1. "Current method to Monitor Loc-RIB" probably needs to be
"Alternative method to monitor Loc-RIB"

s/current/alternative/

### note 7

In section 3, the following change hopefully clarifies that the Loc-RIB
as observed through BMP is a composite of potentially-to-be-redistributed-into-BGP-routes
and routes received from other peers. 

OLD:
It is further defined that the routes selected include locally originated
and routes from all peers.

NEW:
Note that the Loc-RIB state as monitored through BMP might also contain routes
imported from other routing protocols such as an IGP, or local static routes.

### note 8

section 5.3

Curious: why ASCII and not UTF-8 (of which ASCII is a subset)?

### note 9

Section 6.1 states "several methods to implement Loc-RIB efficiently"

is this the implementation of Loc-RIB in a BGP-4 speaker? Or the implementation
of BMP Loc-RIB monitoring?