SSH

We mainly use SSH for the purpose of securely logging into a remote system. Most Linux distributions come with the SSH package, by default. In order to verify whether SSH is currently running, we use the systemctl command; we pass the status option, as follows:

The SSH daemon ssh.service is currently running (particularly, the Secure Shell server). Another method that we can use to verify that the SSH service is running is the netstat command; we pass the ntlp options (n for display port numbers, t for TCP protocol, l for currently listening, and p for program ID/program name), as follows:

root@Linuxplus:/home/philip# netstat -ntlp
Active Internet connections (only servers)
Proto Recv-Q Send-Q Local Address Foreign Address State       PID/Program name   
tcp  0   0  0.0.0.0:514     0.0.0.0:*  LISTEN  519/rsyslogd      
tcp  0   0  127.0.0.53:53   0.0.0.0:*  LISTEN  431/systemd...