From the top menu, select Host > Host Settings > Access Control. The Access Control page opens.
Click Create. The Create Access Control Entry page opens.
This page is used to add an entry to the Access Control list.
Define access controls for. Select the type of access control entry.
A single computer or IP address. Select this option to grant or deny access to a single computer or IP address. If this option is selected, the Net mask field is disabled.
A group of computers. Select this option to grant or deny access to a group of computers or IP addresses.
IP address. Enter the IP address of the computer to be added to the list.
Net mask. If you are defining access for a group of computers, enter the subnet mask for the group. For example, if you have a class C address space of 156.21.50.0, enter a IP address of 156.21.50.0 and a net mask of 255.255.255.0. This will grant or deny access to the 254 systems with the IP address of 156.21.50.1 through 156.21.50.255.