US Patent 10505985 Hostname validation and policy evasion prevention

A request to access a network resource is received from a client device. The request includes a purported hostname of the network resource. A Domain Name System (DNS) lookup of the purported hostname is performed. A result of the lookup is used in making a determination that the request received from the client device is invalid. In response to the determination being made that the request received from the client device is invalid, an action to take with respect to the client device is determined.