The hard disk serial number management function allows you to configure a list of hard disk serial numbers permitted to access the network. Enable the function for Access Policy and configure the permitted hard disk serial number list to restrict the users who can come online. When Access for Endpoints with Hard Disk Serial Numbers Unobtained is set to Permitted, the endpoint is allowed to access the network if UAM cannot obtain its hard disk serial number. When Access for Endpoints with Hard Disk Serial Numbers Unobtained is set to Denied, the endpoint is prohibited from accessing the network if UAM cannot obtain its hard disk serial number. This feature must work with the iNode PC client.