Troubleshooting Network Connectivity

Slow programs and internet

After trying out NetworkManager for the first time, my system coincidentally became sluggish. Firefox took forever to open, and so did webpages. Some commands like mix took damn long to launch too.

There were two underlying issues:

hostname

In /etc/hosts, I needed to add an entry without the .localdomain suffix:

127.0.0.1               <hostname>.localdomain      localhost
127.0.1.1               <hostname>                  localhost

DNS

In /etc/resolv.conf, I manually set Cloudflare's public DNS resolver to bypass the broken upstream ones:

nameserver 1.1.1.1
nameserver 1.0.0.1