Helo guys,
It would be very nice if you can add Content blocking for .avi .zip .mp3 etc…
I know that it can be done via proxy, but it would be much better to block it in firewall.
It would be great to block that, for example in offices where you don’t want from workers to download movies etc..
Cheers…
Second that. I guess MT already can do such things since it can fiter out p2p protocols
I saw this feature in Kerio Firewall, it can enalyze protocols and filter out connections with unwanted contents (viruses, troyans, bad keywords etc…).
My initial posting were wrong and are deleted. 
New answer: Since I have not used the Web proxy, I was not aware of what you could do with that. After reading the f__king manual I discovered the magic of proxying. 
You can acheive the blocking of files such as .avi and .zip. Just read here:
http://www.mikrotik.com/docs/ros/2.8/ip/webproxy
The idea is not using the proxy, which is after all not available for other protocols. COntent filtering may check any protocol, not just http.
The content filter box we employ uses a simple but clever way of doing content filtering. For websites, it simply observes the http traffic for certain website requests. If the website is in a list of block sites, it simply injects a block page. This is a really quick way of doing it. In fact it doesn’t put near the load on the system as a squid box. Because its passive, it doesn’t disrupt the pipe at all.
thx denialsander,
i already did this in one school, but this is not what I write about.
If MT blocks it in the firewall you don’t need to think which protocol they are going to use!
Cheers…