Sometimes, your site may be either hacked or subjected to Denial-of-Service attacks. Immediately, you should try to stop these types of attacks in future. A nice way to do this is to find out the IP address of the attacker and then block that address using the various tools on the server. In most cases, you will not have access to these tools. In such a situation you have to find out alternative ways to resolve the problem.
Community Server includes a built‑in functionality to ban an IP address and it can be accessed by clicking the IP Address Banning link. You should note that this functionality is available only if you have installed the standard version or above of Community Server.
You need to enter the required IP address and click on the Add IP Address button. You can also enter range such as 111.111.11.*. As soon as you click the button the IP address will be displayed on the screen as shown in the screenshot:
Once an IP Address has been blocked it can be deleted...