How to recover from "Too many Authentication Failures for user root"

Are you sure that root login to ssh is allowed?

Check sshd_config and verify that root login is permitted. sshd will need to be restarted if the setting changes.

"Too many Authentication Failures for user root" means that Your SSH server's MaxAuthTries limit was exceeded. It happens so that Your client is trying to authenticate with all possible keys stored in /home/USER/.ssh/ .

This situation can be solved by these ways:

1. ssh -i /path/to/id_rsa root@host
2. Specify Host/IdentityFile pair in /home/USER/.ssh/config

A single host in the config file should look something like this:

Host example.com
  IdentityFile /home/USER/.ssh/id_rsa

You can also set the user so you don't need to enter it on the command line and shorten long FQDN's too, see this example:

host short
  IdentityFile /home/USER/.ssh/id_rsa
  User someuser
  HostName really-long-domain.example.com

You then connect to the really-long-domain.example.com server with:

ssh short

Note: if you choose to use only the second option, and try to use ssh example.com you will still get errors (if that;s what brought you here), the short version will not give the errors, you can also use both options so you can ssh [email protected] without the errors.

3. Increase MaxAuthTries value on the SSH server in /etc/ssh/sshd_config (not recommended).

If you get the following SSH Error:

$ Received disconnect from host: 2: Too many authentication failures for root

This could happen if you have (default on my system) five or more DSA/RSA identity files stored in your .ssh directory. In this case if the -i option isn't specified at the command line the ssh client will first attempt to login using each identity (private key) and next prompt for password authentication. However, sshd drops the connection after five bad login attempts (again default may vary).

So if you have a number of private keys in your .ssh directory you could disable Public Key Authentication at the command line using the -o optional argument.

For example:

$ ssh -o PubkeyAuthentication=no root@host

On the remote machine open /etc/sshd_config and change value

MaxAuthTries 30

This is typical problem when You have installed multiple keys or open multiple connections. Server checking step by step each key and if MaxAuthTries is setup on 3 then after first 3`rd tries will disconnect You. Typical ssh security.

I suggest You to use verbose mode during connection to remote machine to analyze problem.

ssh -v -p port_number user@servername

Guessing like most poeple on this forum do is WRONG and its wasting of time. First try to analyze problem, collect informations and then ask.

Have fun.