R0106-HP MSR Router Series Layer 3 - IP Services Configuration Guide(V7)

Verifying the configuration

DHCP clients can obtain IP addresses and other network parameters from the DHCP server through the

DHCP relay agent. You can use the display dhcp relay statistics command to display the statistics of

DHCP packets forwarded by the DHCP relay agent. If you enable relay entry recording on the DHCP

relay agent with the dhcp relay client-information record command, you can use the display dhcp relay

client-information command to display relay entries.

Option 82 configuration example

Network requirements

As shown in Figure 23, the DHCP relay agent (Router A) replaces Option 82 in DHCP requests before

forwarding them to the DHCP server (Router B).

• The Circuit ID sub-option is company001.

• The Remote ID sub-option is device001.

To use Option 82, you must also enable the DHCP server to handle Option 82.

Configuration procedure

# Specify IP addresses for the interfaces. (Details not shown.)

# Enable DHCP.

<RouterA> system-view

[RouterA] dhcp enable

# Enable the DHCP relay agent on GigabitEthernet 2/1/1.

[RouterA] interface gigabitethernet 2/1/1

[RouterA-GigabitEthernet2/1/1] dhcp select relay

# Specify the IP address of the DHCP server on the relay agent.

[RouterA-GigabitEthernet2/1/1] dhcp relay server-address 10.1.1.1

# Enable the DHCP relay agent to handle Option 82, and perform Option 82 related configuration.

[RouterA-GigabitEthernet2/1/1] dhcp relay information enable

[RouterA-GigabitEthernet2/1/1] dhcp relay information strategy replace

[RouterA-GigabitEthernet2/1/1] dhcp relay information circuit-id string company001

[RouterA-GigabitEthernet2/1/1] dhcp relay information remote-id string device001

Troubleshooting DHCP relay agent configuration

Symptom

DHCP clients cannot obtain configuration parameters through the DHCP relay agent.

Analysis

Some problems might occur with the DHCP relay agent or server configuration.