Re: speedtest.net in multi connections mode causes the FreeBSD 13-CURRENT router to crash

On 2020-08-28 08:02, S.N. Trigub wrote:
> Hi!
> 
> I run FreeBSD 13.0-CURRENT #0 r363772 as router in small office with two
> network interface: sk0 and sk1.
> sk0 connected to 2 providers (main and backup) via VLAN and natd, sk1
> connected to office network via VLAN.
> I had to use VLAN due to cabling issues.
> 
> As soon as the user runs the speedtest.net in browser on any client
> computer in network
> FreeBSD router goes into panic mode and automatically reboot during
> multi connection upload test.
> In single connections mode of speedtest.net all is fine.
> 
> Error is : Fatal trap 12: page fault while in kernel mode.
> 
> In my opinion the error is caused by multiple openings of outgoing
> connections on router in a short period of time.
> This is not a hardware error. I tested it on three different
> motherboards with different kernel versions and diffenent amount of RAM
> (8GB DDR2 and 16, 24, 32GB DDR3).
> Maybe this is somehow due to the use of VLAN, or network card driver
> problem...
> I noticed this problem about six months ago when I switched from FreeBSD
> 12-Current to FreeBSD 13-Current.
> Since then I have been updating the kernel about once a week, but the
> error still present.
> 
> I read on the some artictes in Internet that this can happen when tcp
> extensions are enabled. I disabled tcp_extensons in rc.conf, and
> set some sysctls params as described in Internet-articles, but it didn't
> affect anything.
> The same error sometimes occurs when clients are talking on Skype.
> 
> Could you help me? Any idea is appreciated!
> 
> Thank you.
> Sergei.
> 

Usually, just under the message 'Fatal trap 12: page fault while in
kernel mode.' there will be some other debugging information,
specifically, the 'stack backtrace', which shows where in the code the
crash happened.

If you can manage to capture that, it will be much easier to investigate
your issue.

Here is a random example I managed to find on the internet:

https://preview.redd.it/cch19ymrucy21.png?width=644&format=png&auto=webp&s=bd483ca83d80fb0cdccb9b835d71b6d9812c592e




-- 
Allan Jude