Merlin is a very powerful Router OS.

The best feature I like is its plugin system. there you can install many third-party apps like Adblock, web shell, AppleDNS. Most of the great apps are already in its built-insoftware center you can just install them with 1 click.

It also has a `Firewall`,  here you can add some rules to let the router block some URL or hosts or even IP that you don't want the users access.  

But as it says, it has some limitations:

So basically, since almost all websites are with HTTPS now, this Firewall has actually been useless now.

Of cause, since it's a mini Linux system, you can log in to it in shell and edit  hosts, but it's not that convenient to do things with the shell. 

Here is a killer app, it's been taken down because of Chinese policy, it's called shad0w20cks(you know it). 

In it's DNS Settings, there is a textarea called customize dnsmayou can just add your hosts like rules in it. like if you want to block and



And then save.

works like a charm :D