Dhcp Relay Agent Support For Option 82; Dhcp Relay Agent Configuration Task List - HP 830 Series Configuration Manual

1. After receiving a DHCP-DISCOVER or DHCP-REQUEST broadcast message from a DHCP client,
the DHCP relay agent fills the giaddr field of the message with its IP address and forwards the
message to the designated DHCP server in unicast mode.
2. Based on the giaddr field, the DHCP server returns an IP address and other configuration
parameters in a response to the relay agent, and the relay agent conveys it to the client.

DHCP relay agent support for Option 82

Option 82 records the location information about the DHCP client. It enables the administrator to locate
the DHCP client for security control and accounting purposes. For more information, see
allocation."
If the DHCP relay agent supports Option 82, it handles a DHCP request according to Option 82, if any.
The handling strategies are described in
If a response returned by the DHCP server contains Option 82, the DHCP relay agent removes the
Option 82 before forwarding the response to the client.
Table 3 Handling strategies of the DHCP relay agent
If a DHCP request
has...
Option 82
no Option 82

DHCP relay agent configuration task list

Task
Enabling DHCP
Enabling the DHCP relay agent on an interface
Correlating a DHCP server group with a relay agent interface
Table
Handling Padding
strategy format
Drop Random
Keep Random
normal
Replace verbose
user-defined
N/A normal
N/A verbose
N/A user-defined
40
3.
The DHCP relay agent...
Drops the message.
Forwards the message without changing
Option 82.
Forwards the message after replacing the
original Option 82 with the Option 82
padded in normal format.
Forwards the message after replacing the
original Option 82 with the Option 82
padded in verbose format.
Forwards the message after replacing the
original Option 82 with the user-defined
Option 82.
Forwards the message after adding Option 82
padded in normal format.
Forwards the message after adding the Option
82 padded in verbose format.
Forwards the message after adding the
user-defined Option 82.
"DHCP address
Remarks
Required.
Required.
Required.