Yes it is. There are 2 lines in iptable rules:
70 0 0 DROP all -- !lo * 202.142.165.14 0.0.0.0/0
70 0 0 DROP all -- * !lo 0.0.0.0/0 202.142.165.14
But don't forget that I've blocked these IPs manually.
Finally, I asked a security specialist to solve this problem. And he did.
Now, after a certain login failure, IP will be blocked automatically. But he did not say anything about the problem and its solution