table inet x {
	map z {
		type ipv4_addr . inet_proto . inet_service : ipv4_addr . inet_service
		elements = { 1.1.1.1 . tcp . 20 : 2.2.2.2 . 30 }
	}

	chain y {
		type nat hook prerouting priority dstnat; policy accept;
		meta nfproto ipv4 dnat ip to ip saddr . ip protocol . tcp dport map @z
	}
}