tcp: disable nolocaltimewait and deprecate it
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Authored by tuexen on Jun 26 2025, 7:43 PM.

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glebius
rrs
rscheff
peter.lei_ieee.org
lstewart

Group Reviewers

transport

Summary

Set the default value of the sysctl-variable net.inet.tcp.nolocaltimewait to 0. This will make the behavior compliant with RFC 9293. Furthermore document that using the sysctl-variable is deprecated and will be removed in FreeBSD 16.

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rG FreeBSD src repository

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tuexen created this revision.Jun 26 2025, 7:43 PM

Herald added a reviewer: transport. · View Herald TranscriptJun 26 2025, 7:43 PM

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tuexen requested review of this revision.Jun 26 2025, 7:43 PM

We could also use SYSCTL_PROC() instead of SYSCTL_BOOL() and then add gone_in() to emphasis that the sysctl-variable is deprecated. Just let me know if this is wanted.

Please do! In the past we (at least me & Igor Sysoev) promoted the use of sysctl, so I expect there is a number for people that have it in /etc/sysctl.conf.

Relnotes?

In D51069#1165566, @ziaee wrote:

Relnotes?

Yes.

Add deprecation notice as suggested by gleb.

In D51069#1165514, @glebius wrote:

We could also use SYSCTL_PROC() instead of SYSCTL_BOOL() and then add gone_in() to emphasis that the sysctl-variable is deprecated. Just let me know if this is wanted.

Please do! In the past we (at least me & Igor Sysoev) promoted the use of sysctl, so I expect there is a number for people that have it in /etc/sysctl.conf.

Done.

glebius accepted this revision.Jun 26 2025, 9:56 PM

tuexen edited the summary of this revision. (Show Details)Jun 27 2025, 5:13 AM

peter.lei_ieee.org accepted this revision.Jun 27 2025, 5:23 PM

This revision is now accepted and ready to land.Jun 27 2025, 5:23 PM

This was committed in c3fc0db3bc50.