Why do we even use ad blockers at home when most home routers have filter lists?

Question

I started pretty much like the rest of us with regular ad blocking extensions. But there is arguably a performance drop due to the additional checks each time you load a page.

I then started using Steven Blacks hosts file which was a far more elegant solution because instead of blocking ads individually I would just block their networks all together. Ads do change frequently, but ad networks don't. I've run with this setup now for a while with AdNauseam active but no ads got through yet.

Since I use multiple devices at home, I thought about just using the router internal filter list to do the same stuff my host file does. It should work pretty much the same way, just less effort to keep the blacklist up to date.

So for someone in control of a filtering capable router, is this a valid strategy or am I missing some important point here?

Answer 1

The strategy is a good one since it also protects non-browser apps on your computer(s) as well as other devices on your home network (set-top boxes, IoT, etc). Home routers, when they do offer filter lists, often require entry one at a time, which is quite cumbersome for long lists. Many people also don't know where to get a credible list of elements to block, and block lists take several formats: domains, URLs, servers, etc., with varying degrees of wildcarding. Block lists also need regular maintenance as new domains, servers, IP addresses, etc., get used by tracking companies.

Some browser-based blocking that detects scripts may be difficult to replicate in a simple server or domain list. Also, some device fingerprinting elements (see: https://webtransparency.cs.princeton.edu/webcensus/index.html) may be difficult or impossible to handle at that level.

I always recommend a tiered approach for defense in depth: block at least the largest or most intrusive trackers at the router and/or DNS level, use hosts files, use browser extensions on computers and mobile devices, etc. Of course this makes troubleshooting more difficult when something is blocked, somewhere, that you don't want to be blocked.