[Nottingham] How to remote diagnose network issues?

Chris Booth Chris.Booth at nottingham.ac.uk
Mon Sep 7 14:57:26 UTC 2015

Does this page help?

From: Nottingham [mailto:nottingham-bounces at mailman.lug.org.uk] On Behalf Of Jason Irwin
Sent: 06 September 2015 23:07
To: Notts GNU/Linux Users Group
Subject: [Nottingham] How to remote diagnose network issues?

I am trying to have a RasPi create a a reverse tunnel to a server so I can manage it. This should be simple enough. For some reason I have not yet been able to determine, the connection keeps dropping out. Even with autossh.

My first problem is, what has replaced /etc/network/if-up.d/ in systemd?
I know systemd defines things differently, but no amount of searching has given the the answer to "How to get systemd to run a script when the network is up".
Next is, how do I figure out *why* the connection drops? I've got autossh dumping its error messages to a log file that remains annoyingly empty, I just don't get it. I've run this same thing (autossh -f /path/cert -R 1234:here:22 foo at bar) numerous times and it just, well, works! Only thing different in this case is that the RasPi is on a VPN that can hiccup (which the Pi detects and restarts). Thing is, with autossh, I would expect it to re-connect back to me one the Pi has finished slapping ithe VPN around (regardless of any systemd muck).

Internet connection to the location is also woeful, so any video chat/desktop share is fraught; or I'd use TeamViewer or something access Cygwin on a local lappy. Luckily there is an IT adept out at the location for the next few days.
Any help gratefully received!

This message and any attachment are intended solely for the addressee
and may contain confidential information. If you have received this
message in error, please send it back to me, and immediately delete it. 

Please do not use, copy or disclose the information contained in this
message or in any attachment.  Any views or opinions expressed by the
author of this email do not necessarily reflect the views of the
University of Nottingham.

This message has been checked for viruses but the contents of an
attachment may still contain software viruses which could damage your
computer system, you are advised to perform your own checks. Email
communications with the University of Nottingham may be monitored as
permitted by UK legislation.

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mailman.lug.org.uk/pipermail/nottingham/attachments/20150907/8a7eb60d/attachment.html>

More information about the Nottingham mailing list