H3C Technologies H3C S12500 Series Switches - Manual (Page 82)

68
DHCP relay agent Option 82 support configuration example
Network requirements
As shown in Figure 32 , Option 82 is enabled on the DHCP relay agent (Switch A). The handling strategy
for DHCP requests containing Option 82 is configured as replace. The padding content for the circuit ID
sub-option is configured as company001 and for the remote ID sub-option as device001.
Switch A forwards DHCP requests to the DHCP server (Switch B) after replacing Option 82 in the requests,
so that the DHCP clients can obtain IP addresses.
Configuration procedure
# Specify IP addresses for the interfaces. (Details not shown.)
# Enable DHCP.
system-view
[SwitchA] dhcp enable
# Add DHCP server 10.1.1.1 into DHCP server group 1.
[SwitchA] dhcp relay server-group 1 ip 10.1.1.1
# Enable the DHCP relay agent on VLAN-interface 1.
[SwitchA] interface vlan-interface 1
[SwitchA-Vlan-interface1] dhcp select relay
# Correlate VLAN-interface 1 to DHCP server group 1.
[SwitchA-Vlan-interface1] dhcp relay server-select 1
# Enable the DHCP relay agent to support Option 82, and perform Option 82-related configurations.
[SwitchA-Vlan-interface1] dhcp relay information enable
[SwitchA-Vlan-interface1] dhcp relay information strategy replace
[SwitchA-Vlan-interface1] dhcp relay information circuit-id string company001
[SwitchA-Vlan-interface1] dhcp relay information remote-id string device001
NOTE:
Configurations on the DHCP server are also required to make the Option 82 configurations function
correctly.
Troubleshooting DHCP relay agent configuration
Symptom
DHCP clients cannot obtain any configuration parameters through the DHCP relay agent.
Analysis
Some problems might occur with the DHCP relay agent or server configuration.