Error: SSH_MSG_DISCONNECT - Too Many Authentication Failures During Setup Tests

Issue

A database connector or destination using SSH Tunnel as the Connection Method fails during the Connecting to SSH Tunnel Setup Test with the following error:

SSH_MSG_DISCONNECT: 2 Too many authentication failures

The setup tests do not complete successfully.

Environment

• Product: Fivetran Database connector or destination
• Connection method: SSH Tunnel or Reverse SSH Tunnel

Resolution

To resolve this issue, do the following:

1. Work with your network team to increase the value of the MaxAuthTries keyword in the /etc/ssh/sshd_config file on the SSH host. For more information, see the sshd_config documentation.

   Restart the sshd daemon after changing the MaxAuthTries value for the change to take effect.

2. Check the SSH daemon log for SSH_MSG_DISCONNECT error messages:

   journalctl -p warning -t sshd
   

   Log files are typically found at /var/log/auth.log or /var/log/secure.

Cause

This issue occurs when the SSH client tries multiple key algorithms before finding a match in PubkeyAcceptedAlgorithms, exceeding the MaxAuthTries limit before a successful authentication. The default value for MaxAuthTries is 6.