How to allow root login from one IP address with ssh public keys only

Here’s how you can allow root login from one IP address using SSH public keys in a Linux environment:

1. Make sure the target machine has an SSH server installed, such as OpenSSH.
2. On the target machine, open the SSH configuration file, typically located at /etc/ssh/sshd_config.
3. Find the line that starts with PermitRootLogin and set it to yes:

PermitRootLogin yes

1. Find the line that starts with PasswordAuthentication and set it to no:

PasswordAuthentication no

1. Add the following line at the end of the file to specify the IP address that should be allowed to log in as root using a public key:

Match Address <ip_address>
n PermitRootLogin yes
n PasswordAuthentication no
n PubkeyAuthentication yes

1. Replace <ip_address> with the desired IP address.
2. Save the changes to the file and close it.
3. Restart the SSH server to apply the changes:

systemctl restart ssh

1. On the client machine, generate a public-private key pair using the following command:

ssh-keygen -t rsa

1. Copy the public key to the target machine:

ssh-copy-id root@<target_machine_ip_address>

1. From now on, you should be able to log in as root from the specified IP address using the public key.

n(emmerrealestate.com)