http://git.netfilter.org/nftables/tree/src/parser_bison.y#n1171 (and especially #n1206 and #n1213) would seem to indicate that the following should work... *is* it supposed to work? uname -a Linux pc 4.8.0-32-generic #34-Ubuntu SMP Tue Dec 13 14:30:43 UTC 2016 x86_64 x86_64 x86_64 GNU/Linux nft --version nftables v0.7 (Scrooge McDuck) nft flush ruleset nft list ruleset nft add table inet firewall nft add set inet firewall v4timeoutintervals { type ipv4_addr\; flags interval\; timeout 1h\; } <cmdline>:1:1-89: Error: Could not process rule: Operation not supported add set inet firewall v4timeoutintervals { type ipv4_addr; flags interval; timeout 1h; } ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Either interval or timeout alone works but interval and timeout together don't. Basically, it seems that you can't use timeouts for subnets. - James -- To unsubscribe from this list: send the line "unsubscribe netfilter" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html