04-05-2019, 02:32 PM
I don't really have anything to add to this. @Manal has already posted a very easy explanation from Wikipedia. Not much to add imho. A bit more background information is probably that for this process a special service is necessary that listens to what happens on the network of your VPS to identify the knocking and modify the firewall to open the SSH port once the right ports have been knocked.
A few tutorials:
- https://www.linuxbabe.com/security/secur...ian-ubuntu
- https://tecadmin.net/secure-ssh-connecti...ing-linux/
And for once actually read the tutorial fully and carefully or you will simply fail at an instant and lock yourself out. If you plan on setting this up you have to set it up from a emergency console because your SSH port will obviously be closed during the guide and will only open later on when you start knocking the ports.
Keep your server up to date. Use SSH public key authentication only and use a passphrase on your keys.
A few tutorials:
- https://www.linuxbabe.com/security/secur...ian-ubuntu
- https://tecadmin.net/secure-ssh-connecti...ing-linux/
And for once actually read the tutorial fully and carefully or you will simply fail at an instant and lock yourself out. If you plan on setting this up you have to set it up from a emergency console because your SSH port will obviously be closed during the guide and will only open later on when you start knocking the ports.
Keep your server up to date. Use SSH public key authentication only and use a passphrase on your keys.
![[Image: zHHqO5Q.png]](https://i.imgur.com/zHHqO5Q.png)
