Then, this: table inet filter { map forward_udp.lan { type ipv6_addr . inet_service : interval ipv6_addr . inet_service flags interval elements = { 2001:db8::1 . 20000-24999 : 2001:db8:16e:10::ffee . 20000-24999 } } chain y { ip6 daddr . udp dport @forward_udp.lan } } Note that you require a Linux kernel >= 6.4 which contains this fix: commit a4878eeae39048e6abe85891c714b49dc13fc08c Author: Florian Westphal <fw@xxxxxxxxx> Date: Fri May 12 14:19:47 2023 +0200 netfilter: nf_tables: relax set/map validation checks Probably there is a chance to request to enqueue this for -stable, because a simple look up on a map is something that should be working since day 0. No 'map' keyword, such keyword is only required when you want to make a map lookup, e.g. dnat ip6 to ip6 daddr . udp dport map @forward_udp.lan ^^^^^^^^^^^^^^^^^^^^^ then you make a map lookup using the key above.