Since last week I have been seeing something fishy and it seems to be worsening. I tried many firewalls and they seem to be useless. I blocked all unwanted ports and only few ports are open so I found that my VPS get frozen when Packets per second get's over 20k. I want to know if there is some way to limit pps on opened ports and reject all other connections to the port until the pps get lowered to 10k.
Maybe this has been discussed, or will be available in Google, but I am unable to find (if this type exits) and only I found is this:
iptables -I INPUT -p tcp --dport 1234 -m hashlimit --hashlimit-mode srcip,srcport --hashlimit-name HASHNAME --hashlimit-htable-max 5000 --hashlimit-htable-expire 10000 --hashlimit-above 5/sec -j DROP
But I don't know what this rule means.