Block Websites

how i can block all websites with one command

thanks

ALL websites?

/ip firewall filter add chain=forward protocol=tcp port=80 action=drop

if i want to give access few sites like www.yahoo.com,www.youtube.com,www.hotmail.com.
how i can .


Thanks

then use webproxy and access list to do this.

http://wiki.mikrotik.com/wiki/How_to_Block_Websites_&_Stop_Downloading_Using_Proxy

Like most completely common questions, there’s a wiki entry for that. Always search the manual and wiki first.