Secure Shell Getting started with Secure Shell Installation or Setup
Example
Free version of SSH protocol implementation, OpenSSH is available in all the Linux distributions. It consists of the server and client packages.
Installation
On Debian-based Linux, you can install openssh using
# apt-get install openssh-server openssh-client
On RHEL/CentOS you need to use yum:
# yum install openssh-server openssh-clients
Current Fedora is using dnf instead of yum.
On Arch Linux, use pacman:
# pacman -S openssh
On OSX, the openssh should be already installed.
If you want to use more recent version, you need to install the openssh from brew:
# brew install openssh --with-brewed-openssl --with-keychain-support
TODO Instructions for Windows
Setup
The openssh client does not need any special setup and is ready to use just after installation. You can try that running ssh remote, where the remote is the remote host running ssh server.
The openssh server is usually started after the installation and default setup is applied. If not, you can start it on systemd based systems using
On Debian-based Linux with systemd:
# systemctl start ssh
On RHEL/CentOS/Fedora and Arch Linux:
# systemctl start sshd
Or on upstart systems using
# service sshd start
Configuration
The openssh have configuration files under /etc/ssh/. The client is also reading client configuration in ~/.ssh/config. The server is using a file sshd_config, which contains most of the default values and contains simple key-value pairs. Example:
Protocol 2
PasswordAuthentication yes
ChallengeResponseAuthentication no
UsePAM yes
AcceptEnv LANG LC_CTYPE LC_NUMERIC LC_TIME LC_COLLATE LC_MONETARY
X11Forwarding yes
Subsystem sftp /usr/libexec/openssh/sftp-server
