Troubleshooting my Raspberry Pi's Wireless Issue

It has been almost a week since I decided to self-host my Ghost blog. It was a fun experience and most importantly, I knew a lot of new things that I would not otherwise know. On the less technical side, it inspired me to write more about my learning journey because not only does it solidify what I already know, it also drives me to learn more.

There is a little problem though. My Internet connection is flaky and it causes my blog to be sporadically down throughout the day. This is not intended to be a for-profit blog, however, seeing people share some of my posts while my blog is down was frustrating. I just had to do something about it. I observed the Pi's behavior by writing several BASH scripts and cron jobs that makes sure these events are logged. Sifting through the logs after work, I found out that aside from the ISP problem, there is another queer phenomenon that was happening. Whenever my home router loses Internet connection, the Raspberry Pi will lose its default gateway; it persists even after rebooting the router.

My initial attempts to fix this issue was to mess with the resolve.conf and /etc/network/interfaces configuration files. I tried everything from manual, dhcp and even static. Nothing really fixed the issue and it was still losing the default gateway route whenever the Internet connection goes down. I finally solved this problem by writing a small BASH script:

#!/bin/bash

ping -c1 google.com > /dev/null

if [ $? != 0 ]  
then  
  echo `date` "No network connection, restarting wlan0" >> /home/uplogs.txt
  /sbin/ifdown 'wlan0'
  sleep 5
  /sbin/ifup --force 'wlan0'
else  
  echo `date` "Internet seems to be up" >> /home/uplogs.txt
fi  

The script pings google.com and then checks the exit code. If the ping exited with an error, the Pi restarts the wireless LAN interface. It also logs all these events so that I can check how reliable my Internet connection was throughout the day. It was a quick and dirty fix. Nothing fancy, but it works.

Author

John Crisostomo

Software Engineer, currently interested in React, React Native and GraphQL