Re: # Fssh_packet_write_wait: Connection to 77.183.250.3 port 22: Broken pipe

On Wed, Dec 30, 2020 at 08:04:03AM +0100, Hartmann, O. wrote:
> ...
> 
> # Fssh_packet_write_wait: Connection to XXX.XXX.XXX.XXX port 22: Broken pipe
> 
> The backend is in most cases a CURRENT, 12.1-RELENG or 12.2-RELENG or 12-STABLE server. A
> couple of months ago we moved from 11.3-RELENG to 12.1-RELENG (server side, clients were
> always 13-CURRENT or 12-STABLE). With FreeBSD 11 as the backend, those broken pipes
> occured, but not that frequent and rapid as it is the fact now. 
> 
> The "problem" can be mitigated somehow: running top or using the console prevents the
> broken pipe fault for a while, but it still occurs. Running "screen" (port
> sysutils/screen) does extend the usability of the console for a significant timespan, but
> the broken pipe also occurs randomly, but it takes a significant time to occur.

I have seen messages like that -- from a remote host that has
rebooted or to which the network connection has (otherwise) been
severed.

A couple of things that I do may have (significantly) reduced the
probability that I would encounter what you report under other
conditions.

Context: I work from my laptop, and ssh to ... well, just about
everything: machines in my house; machines at work; machines at work
accessible only from within the VPN hrough a bastion host; machines in
the FreeBSD.org cluster....  Usually concurrently.  The laptop normally
runs FreeBSD stable/12 (freshly built each morning), but it runs head
while I build head on it and for the smoke-test after the build is
complete.

* A long time ago, I placed "ServerAliveInterval 150" in ~/.ssh/config.
  (I suspect that this was well before Nov 2014, which was the
  beginning of my tenure with my current employer.  And yes, I had
  been using the above-described "ssh to everyhing" well before
  then -- I think I got in he habit around 1999, back at Whistle.)

* Whenever I am about to do something "sensitive," I run tmux
  (port/package sysutils/tmux -- same "ecological niche" as screen,
  but I switched from screen to tmux several years ago, and haven't
  looked back.)  This has become enough of a habit that I tend to
  run tmux from "muscle memory."  Or I have set up csh aliasses or
  scripts to "do stuff" that automagically invoke tmux, so I don't
  even notice.

* [Yeah, I wrote "a couple" up there; this is a bonus. :-) ]  I
  don't keep machines up longer than about 175 hours (a little over
  a week) at a stretch: I update my laptop and my "build machine"
  daily, and update the other machines under my control weekly.

> .... 

Peace,
david
-- 
David H. Wolfskill                              david_at_catwhisker.org
While Trump successfully conned a lot of people for a while, in the
end he's just a failure throwing a temper tantrum because he lost.

See https://www.catwhisker.org/~david/publickey.gpg for my public key.