Maybe OP was reporting a client side problem?
I think both replies assumed OP was trying to block activity on the server.
But I found this thread when I was debugging a ~/.ssh/config glitch which caused the wrong key to be used. Since PasswordAuthentication was disabled on the server, I saw "Too many authentication failures".
To the OP if you're still out there, re: to the thread if you want help debugging a client side connection.