Option 82 Supporting Configuration Example - 3Com 5500-SI Configuration Manual

Option 82 Supporting
Configuration Example
Table 287 Enable option 82 supporting on a DHCP relay
Operation
Enable option 82 supporting
on the DHCP relay
Configure the strategy for
the DHCP relay to process
request packets containing
option 82
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 69 Network diagram for option 82 supporting
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.
<S5500> system-view
2 Enable DHCP.
[S5500] 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.
[S5500] interface vlan-interface 100
[S5500-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.
[S5500] dhcp-server 1 ip address 202.38.1.2
5 Map VLAN 100 interface to DHCP server group1.
[S5500] interface Vlan-interface 100
[S5500-Vlan-interface100] dhcp-server 1
Command Description
dhcp relay Required
information enable By default, this function is disabled.
dhcp relay Optional
information By default, the replace policy is adopted,
strategy { drop | that is, the DHCP relay replaces the original
keep | replace } option 82 carried in a request packet with
its own option 82.
DHCP Configuration 289