H3C S3600 Series User Manual

Operation Manual – DHCP
H3C S3600 Series Ethernet Switches-Release 1510 Chapter 2
DHCP Server Configuration
2-3
holds belong to the network segment the interface resides in and are available to
the interface only.
II. The structure of an address pool
The address pools of a DHCP server are hierarchically organized in a tree-like structure.
The root holds the IP address of the natural network segment, the branches hold the
subnet IP addresses, and the leaves holds the IP addresses that are manually bound to
specific clients. The address pools that are of the same level are sorted by their
configuration precedence order. Such a structure enables configurations to be inherited.
That is, the configurations of the natural network segment can be inherited by its
subnets, whose configurations in turn can be inherited by their client address. So, for
the parameters that are common to the whole network segment or some subnets (such
as domain name), you just need to configure them on the network segment or the
corresponding subnets. The following is the details of configuration inheritance.
1) A newly created child address pool inherits the configurations of its parent address
pool.
2) For an existing parent-child address pool pair, when you performs a new
configuration on the parent address pool:
z The child address pool inherits the new configuration if there is no corresponding
configuration on the child address pool.
z The child address pool does not inherit the new configuration if there is already a
corresponding configuration on the child address pool.
2.1.4 DHCP IP Address Preferences
Interfaces of the DHCP server can work in the global address pool mode or in the
interface address pool mode. If the DHCP server works in the interface address pool
mode, it picks IP addresses from the interface address pools and assigns them to the
DHCP clients. If there is no available IP address in the interface address pools, the
DHCP server picks IP addresses from its global address pool that contains the interface
address pool segment and assigns them to the DHCP clients.
A DHCP server assigns IP addresses in interface address pools or global address
pools to DHCP clients in the following sequence:
z IP addresses that are statically bound to the MAC addresses of DHCP clients or
client IDs
z IP addresses that are ever used by DHCP clients. That is, those in the assigned
leases recorded by the DHCP server. If there is no record in the leases and the
DHCP-DISCOVER packets sent by DHCP clients contain option 50 fields, the
DHCP server assigns the IP address requested by option 50.
z The first IP address found among the available IP addresses in the DHCP address
pool.

H3C S3600 Series Specifications

General

Brand	H3C
Model	S3600 Series
Category	Switch
Language	English