OpenSSH is a free tool widely used for remote login on Linux systems. It uses SSH/SecSH protocol suite providing encryption for network services. Its source code is available free to everyone. This article will help you to Install or Update OpenSSH Server on Ubuntu & LinuxMint systems.
Features of OpenSSH
- Open Source Project
- Free Licensing
- Strong Encryption (3DES, Blowfish, AES, Arcfour)
- X11 Forwarding (encrypt X Window System traffic)
- Port Forwarding (encrypted channels for legacy protocols)
- Strong Authentication (Public Key, One-Time Password and Kerberos Authentication)
- Agent Forwarding (Single-Sign-On)
- Data Compression
Click here to know more details about OpenSSH features.
Step 1 – Install/Update OpenSSH Server
OpenSSH Server packages is available under default apt repositories under all versions of operating systems. You can install or update latest OpenSSH server using following command.
sudo apt-get update sudo apt-get install openssh-server
Step 2 – Start/Stop OpenSSH Service
After installing OpenSSH latest packages from default apt repository. You OpenSSH server will start automatically. But if you need to Start, Stop or Restart OpenSSH server from the command line, use the following commands
sudo service ssh start sudo service ssh stop sudo service ssh restart
Step 3 – Open Firewall Port
If you are using iptables to secure your server, use following command to open port for SSH access.
sudo iptables -A INPUT -s 192.168.1.0/24 -p tcp --dport 22 -j ACCEPT
Or if you are using ufw for managing firewall use following command.
sudo ufw allow from 192.168.1.0/24 to any port 22
What Next: 5 Tips to secure openssh-server
I’m running Mininet-VM on Oracle VirtualBox.
When I write “sudo systemctl status ssh” in the Mininet terminal window, it gives me the following error:
*sudo: systemctl: command not found*
so, please help me in this regard!