I recently repurposed an old but still pretty sturdy samsung laptop as a Pi-Hole DNS Server on my home network and so far (just a couple of days in), it seems to be working pretty well. The laptop is running Ubuntu Server and is a headless/gui-less machine that's now sitting in an old stereo cabinet upstairs in a spare bedroom (the cabinet also houses a couple of other old Dell headless/gui-less laptops repurposed similarly for other home network experimentation). I've got some Raspberry Pi's that I could have used for this purpose, but since I had this unused laptop, I figured I'd put it to some use. Also, Pi-Hole runs pretty lean and doesn't require a lot of resources.

I set the Pi-Hole DNS Server up mostly as an experiment in blocking annoying advertiser cookie tracking, but this of course comes with the added benefit of network-wide ad-blocking. Additionally, I also wanted to add some custom DNS entries for some other home network devices, so that I don't have to fumble around as much with IP addresses when referring to network devices. Of course one of the first things I noticed is the blacked out advertising banners on some of the bigger websites such as CNN. There's also those articles you click on sometimes that dispaly an ad in between every paragraph. What I see now in those types of articles are blank placeholders where those ads used to be. Not all ads get blocked, but a very substantial number do. Here's the dashboard from my Pi-Hole showing the amount of traffic that's been filtered out...

Amazingly nearly 25% of DNS queries got blocked. Meaning these were DNS entries that appear in Pi-Hole's default DNS blacklist whose addresses did not get resolved and hence whose traffic my home network never saw. This would otherwise have resulted in a lot of unnecessary ad-tracking traffic. Not surprisingly, responsiveness on all devices on the network, including two cell phones, is noticeably faster than before. I'll keep monitoring everything hoping nothing breaks as a result of this blocking, but I'm liking it so far!