Simple Connection Monitor

Background I have some computers at home on wireless that drop connections every few days. Other devices in the same location do not drop connections, so I believe the problem is not a configuration error. This is my fix, a script that runs 24/7 and pings my router every five seconds. When the ping fails, it automatically attempts a wireless reconnect.

I did not set this up as a system service or a crontab job, I just launch it manually as root.

Pre-requisites This script should run on any recent version of Linux, you just need the GNU Guile Scheme implementation installed. For Debian GNU/Linux and derivatives of Debian like Ubuntu that also use the APT package tool, that would be apt-get install guile or in some cases apt-get install guile-2.0 You will need to run the command as root or with the sudo command, sudo apt-get install guile or sudo apt-get install guile-2.0

On Fedora Linux and other versions of Linux that use the YUM or DNF package tool, do yum install guile or dnf install guile. Again, you need to run the command as root or with the sudo command, sudo yum install guile or sudo yum install guile.

Use You will need to modify connection_mon.sh to have it run the commands you want. On line 17, change: (let ((status (system ping -c 1 -W 2 192.168.1.1 > /dev/null))) and substitute the address of your gateway, e.g. 10.1.1.1, or 192.168.0.1, or whatever that might be.

On line 26, change

(system `nmcli c up ifname wlp3s0 ap 'guywalksintoabar' passwd-file 'passwd-file-guywalkinsintoabar.txt'`)

To do (system ....) where .... is the quoted command you need to run to re-establish your connection. If you need to run multiple commands, just add multiple (system ....) lines for each command. If you need a password file in the nmcli form 802-11-wireless-security.psk:(your wifi password), make sure to add it. In my case, it's passwd-file-guywalksintoabar.txt and it's in the same directory as the script.

To run it, make sure the file is owned by the root user chown root connection_mon.sh or sudo chown root connection_mon.sh then make sure the file is executable chmod u+x connection_mon.sh or sudo chmod u+x connection_mon.sh then run it. The program will 'own' the current terminal until you exit it by restarting your Linux workstation or use Ctrl-C or the 'kill' command to stop it. ./connection_mon.sh

License

This software is released under the GPLv3, see the included LICENSE.txt for details.