Re: [tcpm] 793bis: TCP Quiet Time
Matt Mathis <mattmathis@google.com> Thu, 23 January 2020 06:59 UTC
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From: Matt Mathis <mattmathis@google.com>
Date: Wed, 22 Jan 2020 22:59:06 -0800
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To: Joe Touch <touch@strayalpha.com>
Cc: Fernando Gont <fgont@si6networks.com>, "tcpm@ietf.org" <tcpm@ietf.org>
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Subject: Re: [tcpm] 793bis: TCP Quiet Time
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There are two other changes that have largely made this problem moot: a) ISS and ephemeral port randomization make it extremely unlikely that segments delayed across a reboot will be in sequence for any connections (at the time this was written, both ISS and ephemeral ports were generated by counters starting from fixed integers). b) Although not reflected in policy, the effective MSL of the internet has been declining as it gets faster. There are paths and devices that can delay packets by more than 10 seconds but they don't normally cause packets to be reordered by that much, so a new SYN can't pass an old data segment, which is a requirement for triggering the hazard. I would suggest changing the text to say "a theoretical problem.... that could be fixed by... but for the following reasons it is viewed as being sufficiently unlikely to ignore. Thanks, --MM-- The best way to predict the future is to create it. - Alan Kay We must not tolerate intolerance; however our response must be carefully measured: too strong would be hypocritical and risks spiraling out of control; too weak risks being mistaken for tacit approval. On Wed, Jan 22, 2020 at 10:27 PM Joe Touch <touch@strayalpha.com> wrote: > > > On Jan 22, 2020, at 10:54 AM, Fernando Gont <fgont@si6networks.com> wrote: > > On 8/28/2019 11:39 AM, Gorry Fairhurst wrote: > > OLD, Section: " The TCP Quiet Time Concept" > - Found this section quite amusing. Is this concept widely implemented in > stacks? > > > No. > > > It might be useful to consider this is relevant only for systems that > reboot in under 2 MSL anyway. That’s a good reason most systems don’t need > to care - but a good reason to worry about ignoring this issue as we move > forward. > > I.e., of this concept and its utility, as financial investors advise: > > Past performance is not be a predictor of future results. > > Joe > _______________________________________________ > tcpm mailing list > tcpm@ietf.org > https://www.ietf.org/mailman/listinfo/tcpm >
- [tcpm] review of rev 14 of RFC 793 bis part 1 of … Gorry Fairhurst
- [tcpm] review of rev 14 of RFC 793 bis part 2 of … Gorry Fairhurst
- Re: [tcpm] review of rev 14 of RFC 793 bis part 2… Joe Touch
- Re: [tcpm] review of rev 14 of RFC 793 bis part 2… Joe Touch
- Re: [tcpm] review of rev 14 of RFC 793 bis part 2… Gorry Fairhurst
- Re: [tcpm] review of rev 14 of RFC 793 bis part 2… Gorry Fairhurst
- Re: [tcpm] review of rev 14 of RFC 793 bis part 1… Wesley Eddy
- Re: [tcpm] review of rev 14 of RFC 793 bis part 1… Gorry Fairhurst
- Re: [tcpm] review of rev 14 of RFC 793 bis part 1… Rodney W. Grimes
- Re: [tcpm] review of rev 14 of RFC 793 bis part 1… Wesley Eddy
- Re: [tcpm] review of rev 14 of RFC 793 bis part 1… Jonathan Morton
- Re: [tcpm] review of rev 14 of RFC 793 bis part 1… Rodney W. Grimes
- [tcpm] 793bis: TCP Quiet Time Wesley Eddy
- Re: [tcpm] 793bis: TCP Quiet Time Yuchung Cheng
- Re: [tcpm] 793bis: TCP Quiet Time Neal Cardwell
- Re: [tcpm] 793bis: TCP Quiet Time Matt Mathis
- Re: [tcpm] 793bis: TCP Quiet Time Joe Touch
- [tcpm] 793bis: variable MTU Wesley Eddy
- [tcpm] 793bis: reset generation section Wesley Eddy
- [tcpm] 793bis: IPv6 jumbograms Wesley Eddy
- [tcpm] 793bis: IP ID Wesley Eddy
- Re: [tcpm] 793bis: IP ID David Borman
- Re: [tcpm] 793bis: variable MTU Gorry Fairhurst
- Re: [tcpm] 793bis: IP ID Gorry Fairhurst
- Re: [tcpm] 793bis: IP ID Michael Tuexen
- Re: [tcpm] 793bis: TCP Quiet Time Matt Mathis
- [tcpm] 793bis: dead gateway detection Wesley Eddy
- [tcpm] 793bis: delayed ACKs Wesley Eddy
- Re: [tcpm] 793bis: IP ID David Borman
- Re: [tcpm] 793bis: IP ID Joe Touch
- Re: [tcpm] 793bis: IP ID David Borman
- Re: [tcpm] 793bis: IP ID Joe Touch
- Re: [tcpm] 793bis: IP ID Joe Touch
- Re: [tcpm] 793bis: delayed ACKs Yuchung Cheng
- Re: [tcpm] 793bis: TCP Quiet Time Fernando Gont
- Re: [tcpm] 793bis: IP ID Fernando Gont
- Re: [tcpm] 793bis: IP ID Joe Touch
- Re: [tcpm] 793bis: TCP Quiet Time Joe Touch
- Re: [tcpm] 793bis: TCP Quiet Time Matt Mathis
- Re: [tcpm] 793bis: TCP Quiet Time Fernando Gont
- Re: [tcpm] 793bis: TCP Quiet Time Fernando Gont
- Re: [tcpm] 793bis: IP ID Gorry Fairhurst
- Re: [tcpm] 793bis: IP ID Fernando Gont
- Re: [tcpm] 793bis: IP ID Joe Touch
- Re: [tcpm] 793bis: IP ID Fernando Gont
- Re: [tcpm] 793bis: IP ID Joe Touch
- Re: [tcpm] 793bis: IP ID Fernando Gont
- Re: [tcpm] 793bis: IP ID Joe Touch