Troubleshooting Dhcp Relay Agent Configuration - 3Com 4210G Series Configuration Manual

Configuration procedure
# Specify IP addresses for the interfaces (omitted).
# Enable DHCP.
<SwitchA> 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
You need to perform corresponding configurations on the DHCP server to make the Option 82
configurations function normally.

Troubleshooting DHCP Relay Agent Configuration

Symptom
DHCP clients cannot obtain any configuration parameters via the DHCP relay agent.
Analysis
Some problems may occur with the DHCP relay agent or server configuration. Enable debugging and
execute the display command on the DHCP relay agent to view the debugging information and
interface state information for locating the problem.
Solution
Check that:
The address pool on the same subnet where DHCP clients reside is available on the DHCP
server.
The routes between the DHCP server and DHCP relay agent are reachable.
The relay agent interface connected to DHCP clients is correlated with correct DHCP server group
and IP addresses for the group members are correct.
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