Hi Shunwan,
Thanks for your feedback, indeed you have a point.
Let me summarize the situation, there are two parts to it:
1) rfc7854 defined Stats type 7 and 9 in a way that L flag is required
whereas rfc8671 went for distinct Pre-/Post-policy Stats types; so we
currently have an inconsistency;
2) Errata 7703, while meaning good, went one step too far: it correctly
closed the use of L flag in other messages where that would not apply
(Init, Term, Peer Up, Peer Down) while impairing these two Stats types 7
and 9;
There are two intuitive solutions to remedy the current situation:
a) Patch Errata 7703 and we live with issue #1 above -- low touch but
rather sub-optimal approach;
b) Keep the Errata and do a micro draft to, in lack of better ideas,
retire and mark reserved Stats types 7 and 9 and align those to rfc8671
style, so we issue 4 new Stats types for Pre- and Post- policy -- a bit
more work but a neat outcome.
I am personally in favor of B, the micro draft path. Thoughts?
Paolo
On 9/12/23 08:47, Zhuangshunwan wrote:
Hi All,
I'm a little confused about the usage of L flag in Statistics Report
messages.
When Statistics Report message is used to report the statistics of
Adj-RIB-Out, I agree that the L flag is not required, for the pre-policy
or post-policy is clearly specified for each statistics type:
# The following text is quoted from rfc8671:
# Stat Type = 14: Number of routes in pre-policy Adj-RIB-Out. This
statistics type is 64-bit Gauge.
# Stat Type = 15: Number of routes in post-policy Adj-RIB-Out. This
statistics type is 64-bit Gauge.
# Stat Type = 16: Number of routes in per-AFI/SAFI pre-policy
Adj-RIB-Out. The value is structured as: 2-byte Address Family
Identifier (AFI), 1-byte Subsequent Address Family Identifier (SAFI),
followed by a 64-bit Gauge.
# Stat Type = 17: Number of routes in per-AFI/SAFI post-policy
Adj-RIB-Out. The value is structured as: 2-byte Address Family
Identifier (AFI), 1-byte Subsequent Address Family Identifier (SAFI),
followed by a 64-bit Gauge.
But for Stat Type 7 & 9 in RFC7854, if the L flag is not used, how to
distinguish pre-policy Adj-RIBs-In statistics from post-policy
Adj-RIBs-In statistics ?
# The following text is quoted from rfc7854:
# o Stat Type = 7: (64-bit Gauge) Number of routes in Adj-RIBs-In.
# o Stat Type = 9: Number of routes in per-AFI/SAFI Adj-RIB-In. The
# value is structured as: 2-byte Address Family Identifier (AFI),
# 1-byte Subsequent Address Family Identifier (SAFI), followed by a
# 64-bit Gauge.
I don't know if my understanding is correct, hope to get your advice!
Thanks,
Shunwan
*From:*GROW [mailto:[email protected]] *On Behalf Of *Dhananjay
Patki (dhpatki)
*Sent:* Monday, December 4, 2023 12:55 PM
*To:* Paolo Lucente <[email protected]>; John Scudder <[email protected]>
*Cc:* Rex Fernando (rex) <[email protected]>; [email protected]; Warren Kumari
<[email protected]>
*Subject:* Re: [GROW] [Technical Errata Reported] RFC7854 (7703)
Thanks, Paolo!
--
Regards,
Dhananjay
*From: *Paolo Lucente <[email protected] <mailto:[email protected]>>
*Date: *Sunday, 3 December 2023 at 5:08 AM
*To: *Dhananjay Patki (dhpatki) <[email protected]
<mailto:[email protected]>>, John Scudder <[email protected]
<mailto:[email protected]>>
*Cc: *Rex Fernando (rex) <[email protected] <mailto:[email protected]>>,
[email protected] <mailto:[email protected]> <[email protected]
<mailto:[email protected]>>, Warren Kumari <[email protected]
<mailto:[email protected]>>
*Subject: *Re: [GROW] [Technical Errata Reported] RFC7854 (7703)
Thanks for having filed this errata; this also seems right to me.
Paolo
On 30/11/23 18:06, Dhananjay Patki (dhpatki) wrote:
Thanks John. Waiting to hear other opinions, if any.
--
Regards,
Dhananjay
*From: *John Scudder <[email protected] <mailto:[email protected]>>
*Date: *Wednesday, 29 November 2023 at 1:00 AM
*To: *Dhananjay Patki (dhpatki) <[email protected] <mailto:[email protected]>>
*Cc: *Rex Fernando (rex) <[email protected] <mailto:[email protected]>>, [email protected]
<mailto:[email protected]>
<[email protected] <mailto:[email protected]>>, Warren Kumari
<[email protected] <mailto:[email protected]>>, Rob Wilton
(rwilton) <[email protected] <mailto:[email protected]>>, [email protected]
<mailto:[email protected]> <[email protected] <mailto:[email protected]>>,
[email protected] <mailto:[email protected]>
<[email protected] <mailto:[email protected]>>,
[email protected] <mailto:[email protected]> <[email protected] <mailto:[email protected]>>
*Subject: *Re: [Technical Errata Reported] RFC7854 (7703)
This seems right. Unless anyone else sees a problem with it, I’d say
verify the erratum.
—John
On Nov 16, 2023, at 5:24 AM, RFC Errata System <[email protected]
<mailto:[email protected]>> wrote:
The following errata report has been submitted for RFC7854,
"BGP Monitoring Protocol (BMP)".
--------------------------------------
You may review the report below and at:
https://urldefense.com/v3/__https://www.rfc-editor.org/errata/eid7703__;!!NEt6yMaO-gk!HnufjFK0wFIcNIN5-34vQMqmG8yvUaw6eoTAdyMYnTxkogc1LdAbUJOb_Guugi2ASer_uq6Aaaowjtulif7zJQ$
<https://urldefense.com/v3/__https:/www.rfc-editor.org/errata/eid7703__;!!NEt6yMaO-gk!HnufjFK0wFIcNIN5-34vQMqmG8yvUaw6eoTAdyMYnTxkogc1LdAbUJOb_Guugi2ASer_uq6Aaaowjtulif7zJQ$>
<https://urldefense.com/v3/__https:/www.rfc-editor.org/errata/eid7703__;!!NEt6yMaO-gk!HnufjFK0wFIcNIN5-34vQMqmG8yvUaw6eoTAdyMYnTxkogc1LdAbUJOb_Guugi2ASer_uq6Aaaowjtulif7zJQ$
<https://urldefense.com/v3/__https:/www.rfc-editor.org/errata/eid7703__;!!NEt6yMaO-gk!HnufjFK0wFIcNIN5-34vQMqmG8yvUaw6eoTAdyMYnTxkogc1LdAbUJOb_Guugi2ASer_uq6Aaaowjtulif7zJQ$>>
--------------------------------------
Type: Technical
Reported by: Dhananjay S. Patki <[email protected] <mailto:[email protected]>>
Section: 4.2
Original Text
-------------
* The L flag, if set to 1, indicates that the message reflects
the post-policy Adj-RIB-In (i.e., its path attributes reflect
the application of inbound policy). It is set to 0 if the
message reflects the pre-policy Adj-RIB-In. Locally sourced
routes also carry an L flag of 1. See Section 5 for further
detail. This flag has no significance when used with route
mirroring messages (Section 4.7).
Corrected Text
--------------
* The L flag, if set to 1, indicates that the message reflects
the post-policy Adj-RIB-In (i.e., its path attributes reflect
the application of inbound policy). It is set to 0 if the
message reflects the pre-policy Adj-RIB-In. Locally sourced
routes also carry an L flag of 1. See Section 5 for further
detail. This flag has significance only when used with Route
Monitoring messages.
Notes
-----
The L flag is used to indicate whether the route monitoring update reflects
Adj-RIB-In pre-policy or post-policy (RFC 7854), or Adj-RIB-Out pre-policy or
post-policy (RFC 8671). It does not apply to any message other than the Route
Monitoring message.
Instructions:
-------------
This erratum is currently posted as "Reported". (If it is spam, it
will be removed shortly by the RFC Production Center.) Please
use "Reply All" to discuss whether it should be verified or
rejected. When a decision is reached, the verifying party
will log in to change the status and edit the report, if necessary.
--------------------------------------
RFC7854 (draft-ietf-grow-bmp-17)
--------------------------------------
Title : BGP Monitoring Protocol (BMP)
Publication Date : June 2016
Author(s) : J. Scudder, Ed., R. Fernando, S. Stuart
Category : PROPOSED STANDARD
Source : Global Routing Operations
Area : Operations and Management
Stream : IETF
Verifying Party : IESG
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