Hi All,

This is simple tutorial to Install OpenSSH-Server. I hope this guide make you easy to Install openSSH server. First I want to try running this service in Ubuntu 12.04, but some module is missing, so I prefer to upgrade.

  1. Do apt-get update and apt-get upgrade (If some missing during this steep, it's recommended to upgrade your ubuntu). to upgrade your ubuntu.

      do-release-upgrade  
  apt-get update
  apt-get upgrade


  2. Install OpenSSH Server using command:  

     apt-get install openssh-server

    then hit "Y" to confirm install


  3. When you want to improve your ssh conf, you need to save your default config. It can be disaster recovery when you do something wrong with your improvement config. do this command, To make sshd config default

     cp /etc/ssh/sshd_config /etc/ssh/sshd_config.defaults

  4. verify file that you copy, make sure there is file with name sshd_config.defaults

     ls /etc/ssh/

  5. Change the atribute file sshd_config.defaults for read-only

     chmod 444 /etc/ssh/sshd_config.default
  6. Verify using command:

     ls /etc/ssh/ -l



    Make sure for file sshd_config.default is for read only for all user and group. The atribute should be:

     -r--r--r-- 1 root root  2541 Aug 8 15:19 sshd_config.default

    To increase security your ssh service you can follow this link.
    https://help.ubuntu.com/community/SSH/OpenSSH/Configuring
  7. Try to log in ssh in ubuntu. For this step, I use Putty: