Configuring The Dhcp Server; Overview; Dhcp Address Pool - HP 10500 Series Configuration Manual

Configuring the DHCP server

This chapter shows how to configure DHCP servers.

Overview

The DHCP server is well suited to networks where:
Manual configuration and centralized management are difficult to implement.
•
• IP addresses are limited. For example, an ISP limits the number of concurrent online users, and most
users must acquire IP addresses dynamically.
Most hosts do not need fixed IP addresses.
•
In addition to assigning IP addresses to DHCP clients on a public network, a multi-VPN-instance customer
edge (MCE) serving as the DHCP server can also assign IP addresses to DHCP clients on private
networks. The IP address ranges of public and private networks or those of private networks on the DHCP
server cannot overlap each other. For more information about MCE, see MPLS Configuration Guide.
NOTE:
The term "interface" in the DHCP features collectively refers to Layer 3 interfaces, including VLAN
interfaces and Layer 3 Ethernet interfaces. You can set an Ethernet port as a Layer 3 interface by using the
port link-mode route command (see

DHCP address pool

DHCP address pools include common and extended address pools:
Common address pool—Supports both static binding and dynamic allocation.
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Extended address pool—Supports only dynamic allocation.
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Common address pool structure
The organization of the common address pool database can be compared to a tree. The root of the tree
is the address pool for natural networks, branches are address pools for subnets, and leaves are
addresses statically bound to clients. For the same level address pools, a previously configured pool has
a higher selection priority than a new one.
At the very beginning, subnets inherit network parameters and clients inherit subnet parameters.
Therefore, common parameters (for example, a DNS server address) should be configured at the highest
(network or subnet) level of the tree. IP address lease durations are not inherited.
The new configuration at the higher level (parent) of the tree is:
Inherited if the lower level (child) has no such configuration.
•
Overridden if the lower level (child) has such configuration.
•
NOTE:
The extended address pools on a DHCP server are independent of each other, and no inheritance
relationship exists among them.
Layer 2—LAN Switching Configuration Guide
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