From: Marco Gaiarin <gaio@sv.lnf.it>
To: lartc@vger.kernel.org
Subject: Re: Connection tracking debugging?!
Date: Fri, 04 Jun 2021 15:23:11 +0000 [thread overview]
Message-ID: <20210604152311.GJ3056@sv.lnf.it> (raw)
In-Reply-To: <20210525103639.GF3214@sv.lnf.it>
Mandi! Grant Taylor
In chel di` si favelave...
Sorry for the late answer, but i was busy in other things...
> > How can i 'debug' this issue? Thanks.
> I'd check the output of dmesg to see if you're exhausting the state table.
> If you are, you'll see all sorts of messages from the kernel. At least I did
> when I ran into this years ago. Adding memory addressed the problem then.
No, i've not sayed that, but was the first things i've looked for, no
conntrack table overflow...
> Short of that low hanging fruit I'd start with packet captures so that you
> can watch the traffic flow. I occasionally see invalid traffic after the
> flow should have been closed.
>
> It looks like your client may be sending TCP Reset packets. This could be
> directly related to how different systems terminate a TCP connection. --
> Even if the clients agree, they may be doing something different than the
> connection tracker helper expects, thus causing a subsequent packet to be
> considered invalid after a shorter shutdown.
Could be that passing thru a proxy (SSL/CONNECT, squid) could lead to
more TCP resets? Seems that proxied connection reset more frequently...
I see in proxy cache.log file sometimes:
2021/06/04 12:41:07| TunnelStateData::Connection::error: FD 20: read/write failure: (32) Broken pipe
--
dott. Marco Gaiarin GNUPG Key ID: 240A3D66
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prev parent reply other threads:[~2021-06-04 15:23 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-25 10:36 Connection tracking debugging?! Marco Gaiarin
2021-05-25 17:55 ` Grant Taylor
2021-06-04 15:23 ` Marco Gaiarin [this message]
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