Creating an SSH Server

Steps to turn a Debian machine into an SSH server accessible from other devices.

Requirements

Installation

1. Refresh the package index.

   sudo apt-get update
   

2. Install the openssh-server package.

   sudo apt-get install openssh-server
   

3. Optional: install openssh-client on the machines that will connect to this server.

   sudo apt-get install openssh-client
   

Verification

Check the status of the service.

sudo service ssh status

● ssh.service - OpenBSD Secure Shell server
   Loaded: loaded (/lib/systemd/system/ssh.service; enabled; vendor preset: enabled)
   Active: active (running) since Mon 2020-06-01 11:41:07 -04; 5h 34min ago
     Docs: man:sshd(8)
           man:sshd_config(5)
  Process: 3233 ExecStartPre=/usr/sbin/sshd -t (code=exited, status=0/SUCCESS)
 Main PID: 3234 (sshd)
    Tasks: 1 (limit: 4915)
   Memory: 3.3M
   CGroup: /system.slice/ssh.service
           └─3234 /usr/sbin/sshd -D

...

Auto-start

Control whether the service enables itself at boot.

sudo systemctl enable ssh

To disable auto-start:

sudo systemctl disable ssh

Adjust server settings—such as port and authentication methods—in sshd_config.

sudo nano /etc/ssh/sshd_config

Useful Commands to Identify the Server

Show the server's IP address.

hostname -I

192.168.32.123

Display the server hostname.

hostname

debian

Display the current username.

whoami

admin

References

• Enable SSH on Debian 10