Secure Shell (SSH) is a cryptographic network protocol for operating network services securely on an unsecured network. Typical applications include remote command line, login and remote command execution, but any network service can be secured with SSH.

SSH provides a secure channel through an unsecured network in a client-server architecture, connecting an SSH client application with an SSH server. The protocol specification distinguishes between two main versions, called SSH-1 and SSH-2. The standard TCP port for SSH is 22. SSH is generally used to access Unix-like operating systems, but it can also be used in Microsoft Windows. Windows 10 uses OpenSSH as its default SSH client.

SSH was designed as a replacement for Telnet and for unsecured remote shell protocols, such as the Berkeley rlogin, rsh and rexec protocols. These protocols send information especially passwords in plain text which makes them susceptible to interception and dissemination through packet analysis. The encryption used by SSH is intended to provide confidentiality and integrity of data through an unsecured network, such as the Internet, although files leaked by Edward Snowden indicate that the National Security Agency can sometimes decrypt SSH, which allows them read the content of the SSH sessions.

Restart SSH service on Linux systems

SSH is an acronym for Secure Shell. It is an Internet communication protocol that allows you to log in to Linux or Unix base systems and execute commands. One can exchange files using a secure channel through an insecure network like the Internet. OpenSSH is developed as part of the OpenBSD project and, by default, is installed on modern Linux and in the * BSD family of operating systems, including macOS. This page shows how to restart the ssh service.

Restart SSH service command

For example, the SSHD services rejection command (you must log in as root user). Execute the command according to the Linux distribution you are using.

CentOS / RHEL / Fedora / Redhat Linux restart SSH

Execute the following command:

# /etc/init.d/sshd restart

You could also use the service command:

# service sshd restart

If you are using RHEL / CentOS / Fedora Linux with systemd (for example, RHEL or CentOS v7 / 8), run the following command:

$ sudo systemctl restart sshd

Para reiniciar SSH en Debian / Ubuntu

Ejecutar el siguiente comando:

# / etc / init.d / ssh restart

O

# service ssh restart

O

$ sudo service ssh restart

Si está usando Debian / Ubuntu / Mint Linux con systemd, use el comando systemctl:

$ sudo systemctl restart ssh

FreeBSD reiniciar SSH

# / etc / rc.d / sshd restart

O

$ sudo service sshd restart

OpenBSD Reiniciar el servicio SSH

# /etc/rc.d/sshd restart

O

$ doas /etc/rc.d/sshd restart

UNIX Reiniciar SSH

# kill -HUP `cat / var / run / sshd.pid`

O

# kill -HUP $ (cat /var/run/sshd.pid)

Diez en cuenta que la ubicación de /var/run/sshd.pid puede cambiar. Así que solo busca un poco a través del directorio / var / run /.

OpenSUSE / SUSE Enterprise Linux reiniciar sshd

Ejecutar el siguiente comando:

$ sudo systemctl restart sshd

Arch Linux reiniciar el servidor sshd

Ejecutar el siguiente comando:

$ sudo systemctl restart sshd.service

Para reiniciar en Línea de comando SSH en Apple macOS
Abra la terminal y ejecute el siguiente comando:

$ sudo launchctl unload /System/Library/LaunchDaemons/ssh.plist
$ sudo launchctl load -w /System/Library/LaunchDaemons/ssh.plist

O

$ sudo launchctl stop com.openssh.sshd
$ sudo launchctl start com.openssh.sshd

Slackware Linux reinicia el servidor SSH
Reiniciar ssh es bastante fácil en Slackware, solo ejecuta el siguiente comando como usuario root:

# /etc/rc.d/rc.sshd restart