User Guide
412
Configuring DHCP Service
DHCP L2 Relay Configuration
Step 6
ip dhcp l2relay information circuit-id
string
(Optional) A default circuit ID is preset on the switch, and you can also run this command
to customize the circuit ID. The circuit ID configurations of the switch and the DHCP server
should be compatible with each other.
The default circuit ID is a 4-byte value which consists of 2-byte VLAN ID and 2-byte Port ID.
The VLAN ID indicates which VLAN the DHCP client belongs to, and the Port ID indicates
which port the DHCP client is connected to. For example, if the DHCP client is connected to
port 1/0/1 in VLAN 2, this field is
00:02:00:01
in hexadecimal.
string
: Enter the customized circuit ID with up to 64 characters.
Step 7
ip dhcp l2relay information remote-id
string
(Optional) The switch uses its own MAC address as the default remote ID, and you can also
run this command to customize the remote ID. The remote ID configurations of the switch
and the DHCP server should be compatible with each other.
string:
Enter the remote ID with up to 64 characters.
Step 8
show ip dhcp l2relay information interface { fastEthernet
port
| gigabitEthernet
port
|
port-channel
port-channel-id
}
Verify the Option 82 configuration of the port.
Step 9
end
Return to Privileged EXEC Mode.
Step 10
copy running-config startup-config
Save the settings in the configuration file.
The following example shows how to enable Option 82 on port 1/0/7 and configure the
strategy as replace, the format as normal, the circuit-id as VLAN20 and the remote-id as
Host1:
Switch#configure
Switch(config)#interface gigabitEthernet
1/0/7
Switch(config-if)#ip dhcp l2relay information option
Switch(config-if)#ip dhcp l2relay information strategy replace
Switch(config-if)#ip dhcp l2relay information format normal
Switch(config-if)#ip dhcp l2relay information circut-id
VLAN20
Switch(config-if)#ip dhcp l2relay information remote-id
Host1
Switch(config-if)#show ip dhcp l2relay information interface gigabitEthernet
1/0/7
Interface Option 82 Status Operation Strategy Format Circuit ID Remote ID LAG
--------- ---------------- ------------------ ------- --------- -------- -----
Gi1/0/7 Enable Replace Normal VLAN20 Host1 N/A
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