Configuring DHCP Service
Configuration Examples
User Guide
421
Figure 4-10 Network Topology for Option 82 in DHCP Relay
Gi1/0/2
Gi1/0/1
DHCP Server
192.168.0.59/24
Switch A
DHCP Relay
00:00:FF:FF:27:12
VLAN 2
Group 1
PC
PC
192.168.0.50-192.168.0.100
VLAN 2
Group 2
PC
PC
192.168.0.150-192.168.0.200
VLAN 1
192.168.0.1/24
4.2.2 Configuration Scheme
To meet the requirements, you can configure Option 82 in DHCP Relay on Switch A.
With DHCP Relay enabled, the switch can forward DHCP requests and replies between
clients and the server. With Option 82 enabled, Switch A informs the DHCP server of the
group information of each computer, so that the DHCP server can assign IP addresses of
different address pools to the computers in different groups.
The overview of the configurations are as follows:
1) Configuring Switch A
a. Configure 802.1Q VLAN. Add all computers to VLAN 2. For details, refer to
.
b.
Configure DHCP VLAN relay and enable Option 82 in DHCP Relay. Demonstrated
with T1500-28PCT,
“4.2.3 Configuring the DHCP Relay Switch”
configuration procedures to configure DHCP VLAN Relay in two ways: using the GUI
and using the CLI.
2) Configuring the DHCP Server
The detailed configurations on the DHCP server may be different among different
devices. You can refer to the related document that is for the DHCP server you use.
Demonstrated with a Linux ISC DHCP Server,
“4.2.4 Configuring the DHCP Server”
provides information about how to set its DHCP configuration file.
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