iptables-translate -A INPUT -p tcp -i eth0 --sport 53 -j ACCEPT nft 'add rule ip filter INPUT iifname "eth0" tcp sport 53 counter accept' iptables-translate -A OUTPUT -p tcp -o eth0 --dport 53:66 -j DROP nft 'add rule ip filter OUTPUT oifname "eth0" tcp dport 53-66 counter drop' iptables-translate -I OUTPUT -p tcp -d 8.8.8.8 -j ACCEPT nft 'insert rule ip filter OUTPUT ip protocol tcp ip daddr 8.8.8.8 counter accept' iptables-translate -I OUTPUT -p tcp --dport 1020:1023 --sport 53 -j ACCEPT nft 'insert rule ip filter OUTPUT tcp sport 53 tcp dport 1020-1023 counter accept' iptables -A INPUT -p tcp --tcp-flags ACK,FIN FIN -j DROP nft 'add rule ip filter INPUT tcp flags fin / fin,ack counter drop' iptables-translate -A INPUT -p tcp --syn -j ACCEPT nft 'add rule ip filter INPUT tcp flags syn / fin,syn,rst,ack counter accept' iptables-translate -A INPUT -p tcp --syn --dport 80 -j ACCEPT nft 'add rule ip filter INPUT tcp dport 80 tcp flags syn / fin,syn,rst,ack counter accept' iptables-translate -A INPUT -f -p tcp nft 'add rule ip filter INPUT ip frag-off & 0x1fff != 0 ip protocol tcp counter' iptables-translate -A INPUT ! -f -p tcp --dport 22 nft 'add rule ip filter INPUT ip frag-off & 0x1fff 0 tcp dport 22 counter' iptables-translate -A INPUT -p tcp --tcp-option 23 nft 'add rule ip filter INPUT tcp option 23 exists counter' iptables-translate -A INPUT -p tcp ! --tcp-option 23 nft 'add rule ip filter INPUT tcp option 23 missing counter'