The following steps can help
you determine at what level to configure and assign DHCP options for
clients on your network:
- Add or define new,
custom option types only if you have new software or applications that
requires a nonstandard DHCP option.
- If your network is
large, be conservative and selective when assigning global options.
These options apply to all clients of a DHCP server computer.
- Use scope-level options
for most options that clients are assigned. In most networks, the scope
level is typically the preferred level for assigning options.
- Use class options if you
have a large network or groups of clients with diverse needs that are
able to support membership in option classes (such as Windows 2000
- Use reserved client
options only for clients that have special requirements—for example, if
your intranet has a DNS server that performs forwarding for resolving
Internet DNS names not authoritatively managed on your network. In this
case, you need to add the IP address of an external DNS server on your
DNS server computer. You can configure your DNS server as a reserved
client in DHCP and set this address as another reserved client option.
The DHCP service uses a
bottom-up hierarchy in determining which option to enforce. This
simplifies DHCP management and allows a flexible administration that can
range from server-wide default settings to individualized client
settings when needed for special circumstances.
Following are the basic
rules of how options are used:
- Active global
options always apply unless overridden by scope, class, or reserved
- Active scope options
always apply to any computers obtaining a lease from that scope,
unless overridden by class or reserved options.
- Active class options
always apply to any computers configured as members of that class,
unless overridden by a reserved option.
- Reserved options
override all other possible options.
configured values on a client override any DHCP options of any type