Operation Manual

Configuring DHCP Relay Configuration Example
Configuration Guide
433
3
Configuration Example
3.1 Network Requirements
A company wants to assign IP addresses to all computers in two departments, and there
is only one DHCP server available. It is required that computers in the same department
should be on the same subnet, while computers in different departments should be on
different subnets.
3.2 Configuration Scheme
In the given situation, the DHCP relay feature can satisfy the requirement because DHCP
relay enables DHCP clients from different subnets to share one DHCP server.
The network topology is as the following figure shows. Computers in the marketing
department belong to VLAN 10 which is connected to the switch via port 1/0/8. The
interface address of VLAN 10 is 192.168.2.1/24. Computers in the R&D department belong
to VLAN 20 which is connected to the switch via port 1/0/16. The interface address of
VLAN 20 is 192.168.3.1/24. The DHCP server is connected to the DHCP Relay switch via
port 1/0/5, and its IP address is 192.168.0.59/24.
Figure 3-1 Network Topology
DHCP Server
192.168.0.59/24
VLAN 20
192.168.3.1/24
VLAN 10
192.168.2.1/24
Marketing Dept.
192.168.2.0/24
R&D Dept.
192.168.3.0/24
Switch
DHCP Relay
Te1/0/16
Te1/0/8
Te1/0/5
The overview of the configurations are as follows:
1) Before DHCP Relay configurations, create two DHCP server pools on the DHCP server,
one is on 192.168.2.0/24 and the other is on 192.168.3.0/24. Make sure the DHCP
server can reach all DHCP clients.
2) Configure 802.1Q VLAN. Add all computers in the marketing department to VLAN
10, and add all computers in the R&D department to VLAN 20. For details, refer to
Configuring 802.1Q VLAN
.