Vendor-Specific Options

The DHCP specification enables hardware and software vendors to create their own DHCP options. These options are delivered through the use of the Client Class Identifier option and the Vendor-Specific Options option. If a DHCP client identifies itself as being of a certain class of clients, and the DHCP server has been configured to serve that class of clients, then the DHCP server can respond with a set of options that make sense only to that client type.

Vendor-Specific Options can be used to deliver the JavaOS checksum and JavaOS property settings to the JavaStation during the boot sequence.

• The checksum identifies the JavaOS image that is available from a network server and helps determine whether that image is updated in JavaStation flash memory, as described on "Task 4: Update Flash Memory with New JavaOS". For more information, see "Managing the JavaOS Checksum".

• JavaOS property settings determine the resources JavaOS uses and other JavaOS attributes. JavaOS properties are described in Chapter 9, Setting JavaOS Properties .

The delivery of Vendor-Specific Options to JavaStation clients works as follows. The DHCP client on the JavaStation (the PROM or JavaOS) includes the JavaStation's Client Class Identifier (DHCP Option #60) in every packet sent to the DHCP server. When the DHCP server receives the Client Class Identifier, it can deliver the JavaOS checksum and/or JavaOS property settings in the Vendor-Specific Options if it has been configured to do so.

The JavaStation's Client Class Identifier is specified in the PROM. Table 8-5 lists the Client Class Identifiers for each JavaStation model.

Table 8-5 JavaStation Client Class Identifiers

JavaStation Model	Client Class Identifier
Brick model	SUNW.JDM1
Tower model	SUNW.JSIIep

See "Sample dhcptab File "" for examples of setting the JavaOS checksum and JavaOS properties in dhcptab. Note, however, that JavaOS properties can be delivered to JavaOS using methods other than the DHCP Vendor-Specific Options. See Chapter 9, Setting JavaOS Properties for more information.