1 We need to add an entry to /etc/hosts.allow file.
2 Enter your GoodAccess gateway's Static IP address. See the example for two permitted IP addresses below.
3 Be sure that you've entered the correct IP address to avoid disrupting the access and save the file.
4 Now we need to block access from the rest of the Internet, so edit the /etc/hosts.deny file and save the file with the following
5 Test the access with and without GoodAccess to be sure that the SSH access is protected.
Note: There are several other ways to restrict access to SSH servers like IPTABLES firewall (restrict the access to TCP port 22) or SSH daemon config..