3Com 4200G 12-Port Configuration Manual page 412

398 C 46: DHCP R
HAPTER
Option 82 Supporting
Configuration Example
C
ELAY ONFIGURATION
Network requirements
Two DHCP clients are on the network segment 10.110.0.0 (255.255.0.0). They obtain
IP addresses from a DHCP server through a switch acting as DHCP relay. Option 82
supporting is enabled on the DHCP relay.
Network diagram
Figure 124 Network diagram for option 82 supporting
DHCP client DHCP client DHCP client DHCP client DHCP client DHCP client
Configuration procedure
This example supposes that the routes between the DHCP relay and the DHCP server
are reachable. The following configurations are only for the switch acting as DHCP
relay.
1 Enter system view.
<S4200G> system-view
2 Enable DHCP.
[4200G] dhcp enable
3 Configure the VLAN interface that is to carry out the DHCP relay function: First enter
the corresponding VLAN interface view. Then assign an IP address and a subnet mask
to the VLAN interface so that it is on the same network segment with the two DHCP
clients.
[4200G] interface vlan-interface 100
[4200G-Vlan-interface 100] ip address 10.110.1.1 255.255.0.0
4 Specify the IP address of the DHCP server by configuring the IP address of the DHCP
server to be used by DHCP server group 1.
[4200G] dhcp-server 1 ip address 202.38.1.2
5 Map VLAN 100 interface to DHCP server group1.
[4200G-Vlan-interface100] dhcp-server 1
[4200G-vlan-interface100] quit
6 Return to system view.
[4200G-vlan-interface 100] quit
7 Enable option 82 supporting on the DHCP relay, with the keep keyword specified.
[4200G] dhcp relay information enable
[4200G] dhcp relay information strategy keep
DHCP client DHCP client DHCP client DHCP client DHCP client DHCP client
10.110.0.0 10.110.0.0 10.110.0.0 10.110.0.0 10.110.0.0 10.110.0.0
Ethernet Ethernet Ethernet Ethernet Ethernet Ethernet
10.110.1.1 10.110.1.1 10.110.1.1 10.110.1.1 10.110.1.1 10.110.1.1
Interne Interne Interne Interne Interne Interne
Switch ( DHCP relay ) Switch ( DHCP relay ) Switch ( DHCP relay )
DHCP server DHCP server DHCP server
202.38.1.2 202.38.1.2 202.38.1.2 202.38.1.2 202.38.1.2 202.38.1.2
202.38.1.1 202.38.1.1 202.38.1.1 202.38.1.1 202.38.1.1 202.38.1.1
t t t t t t
Ethernet Ethernet Ethernet Ethernet Ethernet Ethernet
202.38.0.0 202.38.0.0 202.38.0.0 202.38.0.0 202.38.0.0 202.38.0.0