Jakob,
Hi, Jakob:
I understand this is not a good use of time. But since it is in the
spec, I would like to understand the reasons. If there are good reasons
for doing things differently, then they should be documented in the spec
so that people do not question again.
On 5/8/17 12:13 PM, Jakob Heitz (jheitz) wrote:
It is deliberately kept short to minimize the potential for abuse.
128 is ok, and 129- 255 would be considered abuse?
In protocol design we have had so many mistakes related to small
length fields. There is rarely an issue because one field has an
extra byte.
We could have argued about the length. Should it be 100, 120, 127,
but it's not an argument worth wasting time on.
Yes, that is precisely the reason that this value "128" should not be
specified.
Not using the whole range of the length byte opens the door to using
the rest of the range to indicate a future new information field.
You mean "129-255" are reserved rather than "invalid"? Then that should
be made clear in the spec.
Thanks. -- Enke
Thanks,
Jakob.
-----Original Message-----
From: Enke Chen (enkechen)
Sent: Sunday, May 07, 2017 8:44 PM
To: ietf(_at_)ietf(_dot_)org
Cc: draft-ietf-idr-shutdown(_at_)ietf(_dot_)org; idr(_at_)ietf(_dot_)org;
idr-chairs(_at_)ietf(_dot_)org; Enke Chen (enkechen)
<enkechen(_at_)cisco(_dot_)com>
Subject: Re: [Idr] Last Call: <draft-ietf-idr-shutdown-08.txt> (BGP
Administrative Shutdown Communication) to
Proposed Standard
Hi, Folks:
Just spotted this (apologies for not catching it earlier):
The draft specifies only 0 - 128 as valid in the one-octet length field.
Not sure if there is a strong reason for such an apparent over-specification.
It seems to me that the spec can and should be simplified by removing the
restriction, that is, to allow any value (0 - 255) to be valid. That would
also eliminate one error condition for the implementation.
Thanks. -- Enke
---
2. Shutdown Communication
Length: this 8-bit field represents the length of the Shutdown
Communication field in octets. The length value MUST range from 0
to 128 inclusive.
4. Error Handling
If a Shutdown Communication with an invalid Length value,
----
On 5/5/17 10:54 AM, The IESG wrote:
The IESG has received a request from the Inter-Domain Routing WG (idr) to
consider the following document:
- 'BGP Administrative Shutdown Communication'
<draft-ietf-idr-shutdown-08.txt> as Proposed Standard
The IESG plans to make a decision in the next few weeks, and solicits
final comments on this action. Please send substantive comments to the
ietf(_at_)ietf(_dot_)org mailing lists by 2017-05-19. Exceptionally,
comments may be
sent to iesg(_at_)ietf(_dot_)org instead. In either case, please retain the
beginning of the Subject line to allow automated sorting.
Abstract
This document enhances the BGP Cease NOTIFICATION message
"Administrative Shutdown" and "Administrative Reset" subcodes for
operators to transmit a short freeform message to describe why a BGP
session was shutdown or reset. This document updates RFC 4486.
The file can be obtained via
https://datatracker.ietf.org/doc/draft-ietf-idr-shutdown/
IESG discussion can be tracked via
https://datatracker.ietf.org/doc/draft-ietf-idr-shutdown/ballot/
No IPR declarations have been submitted directly on this I-D.
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