To set up a firewall, first you’ll need to purchase it. If you want to use it for a set length of time, you can buy it as a subscription. If you’d rather pay for burst use, you’ll need to have some pre-pay credit in your account.
Select the server that you would like to add a firewall to, and click on the Edit button. Here you’ll see the configuration details, where you can specify what the firewall should block.
There are two input boxes and a dialogue button representing a choice between Accept or Reject. If I want to block a small number of ports and addresses, I would specify these in the ‘Closed ports’ input and select Accept to accept all other traffic. Conversely, if I wanted to accept only a restricted selection I would state these in ‘Open ports’ and set the Policy to reject all other traffic.
The small green tooltip explains the syntax. To block a port simply specify if it’s tcp or udp, then a forward slash, then the port. To block multiple ports just separate the rules with a space. To block a particular address, or IP block, start with the transport type again – in this case - tcp, slash, the address to be blocked, the CIDR mask and finally the port. tcp/10.0.0.0/24/8001
And that’s it. It’s that simple to set up a firewall on your Open Hosting server.