Is there any way to stop youtube for just one user ?
Example:
/ip firewall filter
add action=reject chain=forward content=www.youtube.com out-interface=Your_WAN_interface src-mac-address=PC:MA:CA:DD:RE:SS
Replace Your_WAN_interface and PC:MA:CA:DD:RE:SS with real values and fine-tune it to your needs and to lower CPU usage (i.e. filter only DNS requests).
Thank you very much I will try it and reply to you about it
This will not work. “Content” is not for URL, it is packet content. This way you will also block any webpages that mention youtube in their articles and other things.
yep it did not work 
there is no way to block youtube for certain users ?
OK, this was just an example. Here is version that works:
/ip firewall layer7-protocol
add name=youtube regexp=youtube
/ip firewall filter
add action=drop chain=input dst-port=53 layer7-protocol=youtube protocol=udp src-mac-address=PC:MA:CA:DD:RE:SS place-before=0
add action=drop chain=forward dst-port=53 layer7-protocol=youtube out-interface=Your_WAN_interface protocol=udp src-mac-address=PC:MA:CA:DD:RE:SS place-before=0
First rule works when using DNS server of router, second rule works with remote DNS. Use both rules in case user tries to change DNS. Try this and post your results.
This works. Blocking DNS is about the only real way to stop a site as expansive and dynamic as Youtube - layer7 and content won’t work on https:// connections, which is what Google forces nowadays.
Also - firing the user for screwing around at the office is even more effective.
i use opendns to do that
thanks , i will try them and post what happens
i tried it but it did not work … i put mac address of the clients access point then i tried the mac address of the broad band account logged in and also did not work,i give broadband accounts from a company and not bandwidth