Clients see ssh_exchange_identification: Connection closed by remote host
This was an intermittent problem. One reason could be that ssh property
MaxStartups has been reached. One
of the servers we had was used by many remote users, and it was very slow at authenticating.
To verify the problem, edit
Add the line
Check logs in
If you see something like
Sep 10 20:43:13 bombay sshd: debug1: drop connection #10
It is because MaxStartups has been reached.
Once that is confirmed, edit
LogLevel DEBUG2, and add
MaxStartups 50 (or whatever your needs are)