https://old.andunix.net/ 2026-06-03T21:37:58+00:00 https://old.andunix.net/ https://old.andunix.net/_media/favicon.ico text/html 2017-04-13T20:11:34+00:00 Anonymous (anonymous@undisclosed.example.com) https://old.andunix.net/info/sysadmin/list_open_ports List Open Ports To list the open ports together with the listening processes: netstat -tulpn Here is an example output: Active Internet connections (only servers) Proto Recv-Q Send-Q Local Address Foreign Address State PID/Program name tcp 0 0 0.0.0.0:22 0.0.0.0:* LISTEN 695/sshd tcp6 0 0 :::22 :::* LISTEN 695/sshd udp 0 0 0.0.0.0:55872 … text/html 2015-11-30T12:09:18+00:00 Anonymous (anonymous@undisclosed.example.com) https://old.andunix.net/info/sysadmin/ssh SSH SSH with Public Key Authentication only /etc/ssh/sshd_config Make sure that your SSH config file (sshd_config) contains these settings: PubkeyAuthentication yes PasswordAuthentication no If you changed the config, make sure to restart sshd to activate ist: