H3C Technologies H3C S12500-X Series Switches - Manual (Page 53)

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Enabling handling of Option 82
Perform this task to enable the DHCP server to handle Option 82. Upon receiving a DHCP request that
contains Option 82, the DHCP server adds Option 82 into the DHCP response.
If you disable the DHCP to handle Option 82, it does not add Option 82 into the response message.
You must enable handling of Option 82 on both the DHCP server and the DHCP relay agent to ensure
correct processing for Option 82. For information about enabling handling of Option 82 on the DHCP
relay agent, see "
Configuring Option 82 ."
To enable the DHCP server to handle Option 82:
Step Command Remarks
1. Enter system view. system-view N/A
2. Enable the server to handle
Option 82.
dhcp server relay information enable
By default, handling of
Option 82 is enabled.
Configuring DHCP server compatibility
Perform this task to enable the DHCP server to support DHCP clients that are incompliant with RFC.
Configuring the DHCP server to broadcast all responses
Typically, the DHCP server broadcasts a response only when the broadcast flag in the DHCP request is
set to 1. To work with DHCP clients that set the broadcast flag to 0 but do not accept unicast responses,
configure the DHCP server to ignore the broadcast flag and always broadcast a response.
If a DHCP request is from a DHCP client that has an IP address (the ciaddr field is not 0), the DHCP server
always unicasts a response (the destination address is ciaddr) to the DHCP client regardless of whether
this command is executed.
If a DHCP request is from a DHCP relay agent (the giaddr field is not 0), the DHCP server always unicasts
a response (the destination address is giaddr) to the DHCP relay agent regardless of whether it is
enabled to broadcast all responses.
To configure the DHCP server to broadcast all responses:
Step Command Remarks
1. Enter system view. system-view N/A
2. Enable the DHCP server to
broadcast all responses.
dhcp server always-broadcast
By default, the DHCP server looks at
the broadcast flag to decide
whether to broadcast or unicast a
response.
Configure the DHCP server to ignore BOOTP requests
The lease duration of the IP addresses obtained by the BOOTP clients is unlimited. For some scenarios
that do not allow unlimited leases, you can configure the DHCP server to ignore BOOTP requests.