sudo -s
iptables-save > /etc/iptables/rules.v4
ip6tables-save > /etc/iptables/rules.v6
exit

iptables -N prohibited_traffic
iptables -I INPUT 2 -j prohibited_traffic

iptables -A prohibited_traffic -s SourceIPAddress -j DROP

ip6tables -N prohibited_traffic
ip6tables -I INPUT 2 -j prohibited_traffic

ip6tables -A prohibited_traffic -s SourceIPAddress -j DROP

sudo ufw deny from <ip_address> to any

sudo ufw deny from <ip_address> to any port <some_port>

sudo ufw deny proto tcp from <ip_address> to any port <some_port>

iptables -A INPUT -s IP-ADDRESS -j DROP

iptables -A INPUT -s 192.168.0.100 -j DROP

iptables -A INPUT -s 192.168.0.100 -p tcp --destination-port 80 -j DROP