On Wed, Mar 12, 2025 at 07:44:25PM +0000, Kerin Millar wrote: > On Wed, 12 Mar 2025, at 4:08 PM, Lars Noodén wrote: > > Hello, > > > > In NFTables, I have created a named set called 'bar' in the chain input > > in the table foo. I can add elements to the set manually, > > > > # nft add element ip foo bar { 192.168.2.2 } > > > > However, I am not able to guess the syntax to have a regular NFTables > > rule do the appending automatically. I've tried a lot of permutations > > of the following, but always with fatal errors, > > > > # nft add rule foo input tcp dport 22 counter add @bar { ip saddr } > > Error: Could not process rule: Operation not supported > > add rule foo input tcp dport 22 counter add @bar { ip saddr } > > For the kernel to raise ENOTSUP does not indicate an error of syntax. The bytecode intended for the nftables VM will already have been compiled at this point. > > I suspect that your set has been declared with the "interval" flag in effect, in which case updates from the packet path are not allowed. As far as I can tell, this constraint is undocumented. Maybe Lars forgot to set on the flags dynamic; Where is you set declaration?