Can anyone give me any idea Nftable rules

Question

1.Accept incoming TCP connections ssh (port 22), with a rate limit of 30 connections per minute, per host, and a burst of 5 connections 2.Log accepted ssh connections.

Answer 1

The first rule in the input chain is usually:

ct state established,related counter accept

So it should be sufficient to add the rule:

ct state new tcp dport 22 limit rate 30/minute burst 35 packets log prefix "[nft accept ssh] " counter accept

Putting it all together:

table inet filter {
    chain input {
            type filter hook input priority filter; policy drop;
            ct state established,related counter accept
            ct state new tcp dport 22 limit rate 30/minute burst 35 packets log prefix "[nft accept ssh] " counter accept
    }
}