I'm block HTTPS Port in iptables:
$IPTABLES -A FORWARD -p tcp --dport $HTTPS_PORT -j DROP $IPTABLES -A FORWARD -p tcp --sport $HTTPS_PORT -j DROP $IPTABLES -A FORWARD -p ALL -d $YOUTUBE_IP -j DROP
It's work in local network without proxy.
But I have another network, which works through proxy.
How can I modify this rules to work in network with proxy?
Question wasn't solved, but professor said me that blocking, for example youtube.com through iptables in proxy not good idea. But blocking for example ssh port or another is good.
Then I modified my examples. In my example I have only one site that may access without proxy: vmk.ugatu.ac.ru.
So I show that iptables blocks proxy port 8008 and then clients can't access to internet through proxy, but they can access to vmk.ugatu.ac.ru without proxy. Another example: I block http port and client cant access to vmk.ugatu.ac.ru without proxy.
So question doesn't need to solve, thanks to all for help)