Messages in this thread | | | From | Neal Cardwell <> | Date | Fri, 1 Apr 2022 11:48:29 -0400 | Subject | Re: linux 5.17.1 disregarding ACK values resulting in stalled TCP connections |
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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
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