RFC 3004 (rfc3004) - Page 2 of 6

The User Class Option for DHCP

RFC 3004             The User Class Option for DHCP        November 2000


2. Requirements Terminology

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY" and "OPTIONAL" in this
   document are to be interpreted as described in RFC 2119 [3].

3. DHCP Terminology

   o "DHCP client"
     A DHCP client or "client" is an Internet host using DHCP to obtain
     configuration parameters such as a network address.

   o "DHCP server"
     A DHCP server or "server" is an Internet host that returns
     configuration parameters to DHCP clients.

   o "binding"
     A binding is a collection of configuration parameters, including at
     least an IP address, associated with or "bound to" a DHCP client.
     Bindings are managed by DHCP servers.

4. User Class option

   This option is used by a DHCP client to optionally identify the type
   or category of user or applications it represents.  A DHCP server
   uses the User Class option to choose the address pool it allocates an
   address from and/or to select any other configuration option.

   This option is a DHCP option [1, 2].

   This option MAY carry multiple User Classes.  Servers may interpret
   the meanings of multiple class specifications in an implementation
   dependent or configuration dependent manner, and so the use of
   multiple classes by a DHCP client should be based on the specific
   server implementation and configuration which will be used to process
   that User class option.

   The format of this option is as follows:

         Code   Len   Value
        +-----+-----+---------------------  . . .  --+
        | 77  |  N  | User Class Data ('Len' octets) |
        +-----+-----+---------------------  . . .  --+

   where Value consists of one or more instances of User Class Data.
   Each instance of User Class Data is formatted as follows:





Stump, et al.               Standards Track