lkml.org 
[lkml]   [2022]   [Apr]   [1]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
Date
SubjectRe: linux 5.17.1 disregarding ACK values resulting in stalled TCP connections
On Fri, Apr 1, 2022 at 11:39 AM Neal Cardwell <ncardwell@google.com> wrote:
...
> Jaco, to provide some evidence for this hypothesis, can you please
> re-enable fastopen but also enable the TFO blackhole detection that
> was disabled in v5.14 (213ad73d0607), with something like:
>
> sysctl -w net.ipv4.tcp_fastopen=1
> sysctl -w tcp_fastopen_blackhole_timeout=3600

I would also suggest using Florian's suggestion to log invalid
packets, so perhaps we can get a clue as to why netfilter thinks these
packets are invalid:

sysctl net.netfilter.nf_conntrack_log_invalid=6

> And then after a few hours, check to see if this blackholing behavior
> has been detected:
> nstat -az | grep -i blackhole
> And see if TFO FastOpenActive attempts have been cut to a super-low rate:
> nstat -az | grep -i fastopenactive

Then I would correspondingly echo Florian's suggestion to check
dmesg/syslog/nflog to learn more about the drops.

neal

\
 
 \ /
  Last update: 2022-04-01 18:23    [W:0.112 / U:3.380 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site