RFC 2937 (rfc2937) - Page 2 of 5

The Name Service Search Option for DHCP

RFC 2937        The Name Service Search Option for DHCP   September 2000


Definitions

   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].  This
   document also uses the following terms:

      "DHCP client"

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

      "DHCP server"

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

   Name Service Search Option Format

     The code for this option is 117, and its minimum length is 2 bytes.
     A DHCP server SHOULD return, in its preferred order, the 16-bit,
     network byte order (big-endian [4]) integer option code for the
     name services (the earlier in the list, the more preferred the name
     service).

       Code            Length      Name Service Search Order in Sequence
   0                   1                   2                   3
   0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  |     117       |     Len       |             ns1               |
  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  |             ns2               |             ...               |
  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

     In the above diagram, ns1 and ns2 are 16-bit integers corresponding
     to two DHCP options which specify the IP addresses of two different
     types of name server.  The current list of name services and their
     DHCP option codes, taken from RFC 2132, includes

       Name Service                                  Value

       Domain Name Server Option                       6
       Network Information Servers Option             41
       NetBIOS over TCP/IP Name Server Option         44
       Network Information Service+ Servers Option    65






Smith                       Standards Track