H3C S7500 Series Operation Manual page 638

Operation Manual – DHCP
H3C S7500 Series Ethernet Switches
assigning is carried out through DHCP relay agent. Note that DHCP server
configuration is the same in both scenarios.
I. Network requirements
The DHCP server assigns IP addresses dynamically to the DHCP clients on the same
network segment. The network segment 10.1.1.0/24, to which the IP addresses of the
address pool belong, is divided into two sub-network segments: 10.1.1.0/25 and
10.1.1.128/25. The switch operating as the DHCP server hosts two VLANs, whose
interface IP addresses are 10.1.1.1/25 and 10.1.1.129/25 respectively.
The DHCP settings of the 10.1.1.0/25 network segment are as follows:
Lease time: 10 days plus 12 hours
Domain name: aabbcc.com
DNS server: 10.1.1.2
WINS server: none
Gateway: 10.1.1.126
The DHCP settings of the 10.1.1.128/25 network segment are as follows:
Lease time: 5 days
Domain name: aabbcc.com
DNS server: 10.1.1.2
WINS server: 10.1.1.4
Gateway: 10.1.1.254
Note:
If you use the inheriting relation of parent and child address pools, make sure that the
number of the assigned IP addresses does not exceed the number of the IP
addresses in the child address pool; otherwise extra IP addresses will be obtained
from the parent address pool. The attributes (for example, gateway) also are based
on the configuration of the parent address pool.
For example, in the network to which VLAN-interface 1 is connected, if multiple clients
apply for IP addresses, the child address pool 10.1.1.0/25 assigns IP addresses first.
When the IP addresses in the child address pool have been assigned, if other clients
need IP addresses, the IP addresses will be assigned from the parent address pool
10.1.1.0/24 and the attributes will be based on the configuration of the parent address
pool.
For this example, the number of clients applying for IP addresses from
VLAN-interface 1 is recommended to be less than or equal to 122 and the number of
clients applying for IP addresses from VLAN-interface 2 is recommended to be less
than or equal to 124.
Chapter 2 DHCP Server Configuration
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