A Linux administrator is configuring a two-node cluster and needs to be able to connect the nodes to each other using SSH keys from the root account…

The ssh-copy-id command is used to copy a public SSH key from a local machine to a remote server

and add it to the authorized_keys file, which allows passwordless authentication between the

machines. The administrator can use this command to copy the root user’s public key from nodea to

nodeb, and vice versa, to enable SSH access between the nodes without entering a password every

time. For example: [root@nodea ssh-copy-id -i ~/.ssh/id_rsa root@nodeb]. The ssh command is used

to initiate an SSH connection to a remote server, but it does not copy any keys. The scp command is

used to copy files securely between machines using SSH, but it does not add any keys to the

authorized_keys file. The ssh-add command is used to add private keys to the SSH agent, which

manages them for SSH authentication, but it does not copy any keys to a remote server.