This article made by Foss Post generated a good amount of discussion towards fwupd and LVFS, so I decided to verify what are the domains used by them. This post is not meant to discuss if you agree with your hardware information being sent to third-party servers or not, this post is aimed at those who value their privacy and don't want to share information about their systems.
I downloaded the latest version of Ubuntu 18.04 and made a bootable flash drive to check which domains are used by fwupd and LVFS. I used Pi-Hole to verify the DNS queries.
Upon boot I ran the following commands, as described in the GitHub page.
fwupdmgr get-devices fwupdmgr refresh fwupdmgr get-updates fwupdmgr update
The DNS requests made by the commands are the following:
Even though the main domain wasn't triggered, I recommend blocking it as well.
If you wish to blacklist the domains above, you can do it using a hosts file, Pi-Hole or your router, if your equipment provides this feature. It's worth mentioning that even if you don't use Gnome, you might have fwupd installed, especially if you use a desktop environment based on Gnome. I use Linux Mint 18.3 (Cinnamon) and I found fwupd on my system.