How to fix maximum authentication attempts exceeded for user in SSH

First, verify you're using the right SSH key. List all keys in your ssh-agent:

ssh-add -l

If you have many keys, identify which one is authorized on the target server. You may need to check the server's ~/.ssh/authorized_keys file or contact your administrator.

Instead of letting ssh-agent try all keys, specify the exact key to use:

ssh -i /path/to/correct/private/key username@hostname

This bypasses ssh-agent and avoids wasting authentication attempts on wrong keys.

Edit or create ~/.ssh/config and add:

Host *
    IdentitiesOnly yes
    IdentityFile ~/.ssh/id_ed25519
    IdentityFile ~/.ssh/id_rsa

This tells SSH to only try the listed keys instead of offering every key in ssh-agent. Order them so the correct key is attempted first.

For a specific host:

Host example.com
    IdentitiesOnly yes
    IdentityFile ~/.ssh/server_specific_key

If you have many keys, remove the ones you don't need:

# Remove a specific key
ssh-add -d /path/to/key

# Remove all keys
ssh-add -D

Then add back only the keys you actively use:

ssh-add ~/.ssh/id_rsa
ssh-add ~/.ssh/id_ed25519

Run SSH with verbose output to see which keys are attempted and in what order:

ssh -vvv username@hostname

Look for lines like:

debug1: Trying private key: /home/user/.ssh/id_rsa
debug1: Trying private key: /home/user/.ssh/id_ed25519

This shows you the order keys are tried and which ones are rejected.

If you administer the SSH server and legitimate users have multiple keys, you can increase the limit. Edit /etc/ssh/sshd_config:

# Change from default (usually 6) to a higher value
MaxAuthTries 10

Then restart SSH:

sudo systemctl restart sshd
# or
sudo service sshd restart

Warning: Keep this reasonable (4-6 recommended by security standards). Setting it too high increases brute-force attack risk.