Dhcp Relay Agent Support For Option 82 - HP 10500 Series Configuration Manual

Figure 30 DHCP relay agent work process
As shown in
1.
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.
Based on the giaddr field, the DHCP server returns an IP address and other configuration
2.
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 of the DHCP client. It enables the administrator to locate the
DHCP client for security control and accounting purposes. For more information, see
DHCP relay
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
Figure 30, after receiving a DHCP-DISCOVER or DHCP-REQUEST broadcast message
agent."
Handling
strategy
Drop
Keep
Replace
N/A
Table 3.
Padding
The DHCP relay agent will...
format
Random Drop the message.
Forward the message without changing
Random
Option 82.
Forward the message after replacing the
Normal original Option 82 with the Option 82
padded in normal format.
Forward the message after replacing the
Verbose original Option 82 with the Option 82
padded in verbose format.
Forward the message after replacing the
original Option 82 with the user-defined
User-defined
Option 82.
Forward the message after adding Option 82
Normal
padded in normal format.
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"Configuring the