Windows Server 2003 Network Administration

Appendix A. DHCP Options

The TCP/IP configuration values exchanged by a DHCP server and a client are called DHCP options . There are great many DHCP configuration options. While Table A-1 covers a large number of these, it does not cover them all. It does, however, cover all of the DHCP options that are listed under Available Options in the Scope Options window. In fact, it covers more than the options listed there. The additional options covered in the table are:

• Those options discussed in Chapter 5 that the client sends to the server to identify itself as a member of a user or vendor class

• Some additional options described in RFC 2132, DHCP Options and BOOTP Vendor Extensions

• The Classless Static Routes option defined in RFC 3442, Classless Static Route Option for DHCPv4

• The LCI option defined in RFC 3825, Dynamic Host Configuration Protocol Option for Coordinate-based Location Configuration Information, which was used as an example in the text

Table A-1. DHCP options

Code	Name	Description/value
1	Subnet mask	A signed 32-bit integer that specifies the address mask of the client subnet. Defined in the New Scope Wizard or the Scope Properties dialog. Cannot be set in the Scope Options or Server Options dialogs.
2	Time offset	A signed 32-bit integer that specifies the client’s offset from Universal Coordinated Time (UCT) in seconds.
3	Router	A preference-ordered list of IP addresses for routers on the client’s subnet.
4	Time server	A preference-ordered list of IP addresses of the RFC 868 time servers ...