Configure Network Services - MCSA Windows Server 2012 R2: Installation and Configuration Study Guide - page 118

asterisk ( * ) as a wildcard. For example, one of my servers has two network cards: an Intel
EtherExpress (ELNK1) and a generic 100Mbps card. If you want to renew DHCP settings
for both adapters, you can type ipconfig / renew * . If you just want to renew the Intel
EtherExpress card, you can type ipconfig / renew ELNK1 .
Understanding Scope Details
By now you should have a good grasp of what a lease is and how it works. To learn how
to configure your servers to hand out those leases, however, you need to have a complete
understanding of some additional topics: scopes, superscopes, exclusions, reservations,
address pool, and relay agents.
Scope
Let's start with the concept of a scope , which is a contiguous range of addresses. There's
usually one scope per physical subnet, and a scope can cover a Class A, Class B, or Class C
network address or a TCP/IP v6 address. DHCP uses scopes as the basis for managing and
assigning IP addressing information.
Each scope has a set of parameters, or scope options, that you can configure. Scope
options control what data is delivered to DHCP clients when they're completing the DHCP
negotiation process with a particular server. For example, the DNS server name, default
gateway, and default network time server are all separate options that can be assigned.
These settings are called option types . You can use any of the types provided with
Windows Server 2012 R2, or you can specify your own.
Superscope
A superscope enables the DHCP server to provide addresses from more than one scope to
clients on the same physical subnet. This is helpful when clients within the same subnet
have more than one IP network and thus need IPs from more than one address pool.
Microsoft's DHCP snap-in allows you to manage IP address assignment in the superscope,
though you must still configure other scope options individually for each child scope.
Exclusions and Reservations
The scope defines what IP addresses could potentially be assigned, but you can influence
the assignment process in two additional ways by specifying exclusions and reservations:
Exclusions These are IP addresses within the range that you never want automatically
assigned. These excluded addresses are off-limits to DHCP. You'll typically use exclusions
to tag any addresses that you never want the DHCP server to assign at all. You might use
exclusions to set aside addresses that you want to assign permanently to servers that play a
vital role in your organization.
Reservations These are IP addresses within the range for which you want a permanent
DHCP lease. They essentially reserve a particular IP address for a particular device. The
device still goes through the DHCP process (that is, its lease expires and it asks for a new
one), but it always obtains the same addressing information from the DHCP server.