For nftables it's even in the upstream documentation https://wiki.nftables.org/wiki-nftables/index.php/Port_knocking_example https://wiki.nftables.org/wiki-nft

For nftables it's even in the upstream documentation https://wiki.nftables.org/wiki-nftables/index.php/Port_knocking_example https://wiki.nftables.org/wiki-nftables/index.php/Port_knock...