From: Gilad Ben-Yossef <gilad@codefidence.com>
To: Rick Jones <rick.jones2@hp.com>
Cc: netdev@vger.kernel.org, ori@comsleep.com
Subject: Re: [PATCH RFC] Per route TCP options
Date: Wed, 21 Oct 2009 10:04:06 +0200 [thread overview]
Message-ID: <4ADEC076.2030105@codefidence.com> (raw)
In-Reply-To: <4ADDE4C4.5080501@hp.com>
Rick Jones wrote:
> Gilad Ben-Yossef wrote:
>> Turn the global sysctls allowing disabling of TCP SACK, DSCAK,
>> time stamp and window scale into per route entry feature options,
>> laying the ground to future removal of the relevant global sysctls.
>>
>> You really only want to disable SACK, DSACK, time stamp or window
>> scale if you've got a piece of broken networking equipment somewhere
>> as a stop gap until you can bring a big enough hammer to deal with
>> the broken network equipment. It doesn't make sense to "punish" the
>> entire connections going through the machine to destinations not
>> related to the broken equipment.
>
> Is it really only the case that those options get disabled for broken
> networking equipment? Does this presage making all TCP options
> per-route only?
Well, I assume it might be the case that there are situations where you
are trying to communicate over some exotic link where the networking
equipment is not broken as such, but the unusual properties of the link
makes one of the features not desirable. I can't think of such a
situation right now off the top of my head, but maybe they exist.
The point is that even then you are more then likely to wish to turn off
these options to specific destination and routes (that go over said
exotic link) and keep using them over others - e.g. timestamp OK for
local LAN, but for default route that goes over exotic TCP/IP over
carrier penguins turn it off.
To sum it up, I think making these options per route is a win no matter
the situation. The question I am less certain about if it is also
desirable to have a global kill switch in addition to the per route
options. My gut feeling is that this is not needed once you have a per
route option.
Cheers,
Gilad
--
Gilad Ben-Yossef
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next prev parent reply other threads:[~2009-10-21 8:04 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-10-20 15:22 [PATCH RFC] Per route TCP options Gilad Ben-Yossef
2009-10-20 15:22 ` [PATCH RFC] Only parse time stamp TCP option in time wait sock Gilad Ben-Yossef
2009-10-20 15:22 ` [PATCH RFC] Allow tcp_parse_options to consult dst entry Gilad Ben-Yossef
2009-10-20 15:22 ` [PATCH RFC] Add dst_feature to query route entry features Gilad Ben-Yossef
2009-10-20 15:22 ` [PATCH RFC] Add the no SACK route option feature Gilad Ben-Yossef
2009-10-20 15:22 ` [PATCH RFC] Allow disabling TCP timestamp options per route Gilad Ben-Yossef
2009-10-20 15:22 ` [PATCH RFC] Allow to turn off TCP window scale opt " Gilad Ben-Yossef
2009-10-20 15:22 ` [PATCH RFC] Allow disabling of DSACK TCP option " Gilad Ben-Yossef
2009-10-20 15:22 ` [PATCH RFC] Document future removal of sysctl_tcp_* options Gilad Ben-Yossef
2009-10-21 1:40 ` [PATCH RFC] Allow to turn off TCP window scale opt per route Stephen Hemminger
2009-10-21 8:18 ` Gilad Ben-Yossef
2009-10-20 15:44 ` [PATCH RFC] Per route TCP options Eric Dumazet
2009-10-20 16:11 ` Gilad Ben-Yossef
2009-10-20 18:53 ` Ilpo Järvinen
2009-10-21 8:15 ` Gilad Ben-Yossef
2009-10-20 16:26 ` Rick Jones
2009-10-21 8:04 ` Gilad Ben-Yossef [this message]
2009-10-21 8:21 ` Florian Westphal
2009-10-21 8:40 ` Gilad Ben-Yossef
2009-10-21 0:36 ` David Miller
2009-10-21 8:10 ` Gilad Ben-Yossef
2009-10-21 2:13 ` Bill Fink
2009-10-21 8:27 ` Gilad Ben-Yossef
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