sudo apt update
Hit:1 https://repo.skype.com/deb stable InRelease
Hit:2 https://updates.signal.org/desktop/apt xenial InRelease
Hit:3 https://download.docker.com/linux/ubuntu bionic InRelease
Err:4 http://ppa.launchpad.net/graphics-drivers/ppa/ubuntu bionic InRelease
  Connection failed [IP: 91.189.95.83 80]
Err:5 http://ca.archive.ubuntu.com/ubuntu bionic InRelease
  Connection failed [IP: 91.189.91.14 80]
Err:6 http://ca.archive.ubuntu.com/ubuntu bionic-updates InRelease
  Connection failed [IP: 91.189.91.24 80]