User class mask

When sending requests to DHCP servers, some DHCP clients submit a vendor-class ID and/or a user-class ID. This usually allows the manufacturer or even the specific device class of the client to be identified. The DHCP server can use this information to provide the best suited DHCP options for the given device type. This is especially relevant for DHCP option 43, as its content is not standardized, but vendor-specific—the DHCP server has to transmit different information depending on the manufacturer or device type. The two fields "Vendor-class mask" and "User-class mask" can be used as filters. Strings that the DHCP server requires to be present in incoming requests can be entered here. The DHCP option is only delivered when the configured filter matches the DHCP request. The wildcards "*" (any number of characters) and "?" (exactly one character) can be used. If the fields are empty, they are ignored and the option is always delivered.