Ubuntu 20.04 LTS : OpenSSH : Password Authentication : Server World (2024)

	Configure SSH Server to manage a server from the remore computer. SSH uses 22/TCP.
[1]	Password Authentication for OpenSSH Server on Ubuntu is enabled by default, so it's possible to login without changing any settings. Furthermore, root account is prohibited Password Authentication by default with [PermitRootLogin prohibit-password], so default setting is good for use. But if you prohibit root login all, change like follows.

root@dlp:~#

apt -y install openssh-server

root@dlp:~#

vi /etc/ssh/sshd_config

See Also

How To Setup SSH key in Windows

# line 34: uncomment and change to [no]

PermitRootLogin

root@dlp:~#

systemctl restart ssh

SSH Client : Ubuntu

	Configure SSH Client for Ubuntu.
[2]	Install SSH Client.

root@client:~#

apt -y install openssh-client

[3]	Connect to the SSH server with a common user.

# ssh [username@hostname or IP address]

root@client:~#

ssh ubuntu@dlp.srv.world

The authenticity of host 'dlp.srv.world (10.0.0.30)' can't be established.ECDSA key fingerprint is SHA256:0TfV//D7JSem+SOtN5rksAvfE0bXlFw3dWX+w5ri8i8.Are you sure you want to continue connecting (yes/no/[fingerprint])? yesWarning: Permanently added 'dlp.srv.world,10.0.0.30' (ECDSA) to the list of known hosts.ubuntu@dlp.srv.world's password:Welcome to Ubuntu 20.04 LTS (GNU/Linux 5.4.0-26-generic x86_64)..........

ubuntu@dlp:~$

# just logined

[4]	It's possbile to execute commands on remote Host with adding commands to ssh command.

# for example, open [/etc/passwd] on remote host

ubuntu@client:~$

ssh ubuntu@dlp.srv.world "cat /etc/passwd"

ubuntu@dlp.srv.world's password:

root:x:0:0:root:/root:/bin/bashdaemon:x:1:1:daemon:/usr/sbin:/usr/sbin/nologinbin:x:2:2:bin:/bin:/usr/sbin/nologinsys:x:3:3:sys:/dev:/usr/sbin/nologinsync:x:4:65534:sync:/bin:/bin/sync..........

SSH Client : Windows#1

	Configure SSH Client for Windows.
[5]	Get a SSH Client for Windows. This example shows to use Putty like follows. Input your server's IP address and Click [Open] button.

[6]	After authentication on SSH server, it's possible to login remotely with SSH.

SSH Client : Windows #2

[7]	If your Windows is Windows 10 Version 1803, OpenSSH Client has been implemented as a Windows feature, so it's possible to use ssh command on PowerShell or Command Prompt without Putty and other SSH software.