14.4. OpenSSH Clients
To connect to an OpenSSH server from a client machine, you must have the openssh-clients and openssh packages installed (see Section 8.2.4, “Installing Packages” for more information on how to install new packages in Red Hat Enterprise Linux).
14.4.1. Using the ssh Utility
sshutility allows you to log in to a remote machine and execute commands there. It is a secure replacement for the
Similarly to the
telnetcommand, log in to a remote machine by using the following command:
For example, to log in to a remote machine named
penguin.example.com, type the following at a shell prompt:
This will log you in with the same user name you are using on the local machine. If you want to specify a different user name, use a command in the following form:
For example, to log in to
The first time you initiate a connection, you will be presented with a message similar to this:
The authenticity of host 'penguin.example.com' can't be established. RSA key fingerprint is 94:68:3a:3a:bc:f3:9a:9b:01:5d:b3:07:38:e2:11:0c. Are you sure you want to continue connecting (yes/no)?
yesto confirm. You will see a notice that the server has been added to the list of known hosts, and a prompt asking for your password:
Warning: Permanently added 'penguin.example.com' (RSA) to the list of known hosts. firstname.lastname@example.org's password:
Update the host key of an SSH server if the key changes. The client notifies the user that the connection cannot proceed until the server's host key is deleted from the
~/.ssh/known_hostsfile. Contact the system administrator of the SSH server to verify the server is not compromised, then remove the line with the name of the remote machine at the beginning.
After entering the password, you will be provided with a shell prompt for the remote machine.
sshprogram can be used to execute a command on the remote machine without logging in to a shell prompt:
For example, the
/etc/redhat-releasefile provides information about the Red Hat Enterprise Linux version. To view the contents of this file on
ssh email@example.com cat /firstname.lastname@example.org's password: Red Hat Enterprise Linux Server release 6.2 (Santiago)
After you enter the correct password, the user name will be displayed, and you will return to your local shell prompt.