46 DOMINION SX I NSTALLATION AND O PERATIONS MANUALIP ACLOverviewThe IP ACL (Access Control List) Tab provides additional security by allowing Administrators to limit the clientmachines that can access the unit. Administrators can specify either specific IP addresses or ranges of IP addressesof machines that cannot connect to the unit.For convenience, all desired IP addresses and subnet addresses can be stored in the IP ACL list and allowed ordisallowed as needed.Figure 48 IP ACL Configuration DisplayConfigure IP ACL Parameters• IP ACL Enabled: Check this box that enables this feature• IP Address Range: Valid IP address range that will be restricted• Subnet Mask: Subnet mask addressImportant! Please make absolutely certain that all IP addresses have been entered correctly beforeenabling IP ACL. If not, you may be locked out of the unit and be unable to access the unit in the future;the only way to restore access to the unit is to perform a factory reset, removing all user-defined valuesthat you have programmed in and forcing you to reconfigure the unit completely.Only valid subnet masks can be entered in the interface. IP addresses 0.0.0.0 and 255.255.255.255 cannot be addedas they are reserved IP addresses. Access to the unit is determined by doing a binary AND of the configured IPaddress with the specified subnet mask, and comparing this with the result of the binary AND of the IP address ofthe machine trying to connect to unit and the specified subnet mask. If the results are the same, access to the unit isdenied.
