RFC 2937 (rfc2937) - Page 2 of 5
The Name Service Search Option for DHCP
Alternative Format: Original Text Document
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
