D-Link DES-3528 User Manual page 53

xStack DES-3528 Series Layer 2 Stackable Fast Ethernet Managed Switch User Manual
DHCP Relay Agent
Information Option 82
Check
DHCP Relay Agent
Information Option 82
Policy
Click Apply to implement any changes that have been made.
NOTE: If the Switch receives a packet that contains the option-82 field from a DHCP client and the
information-checking feature is enabled, the switch drops the packet because it is invalid. However, in
some instances, you might configure a client with the option-82 field. In this situation, you should
disable the information-check feature so that the switch does not remove the option-82 field from the
packet. You can configure the action that the switch takes when it receives a packet with existing
option-82 information by configuring the DHCP Agent Information Option 82 Policy.
check and policy settings will have no effect.
This field can be toggled between Enabled and Disabled using the pull-down menu. It is
used to enable or disable the Switches ability to check the validity of the packet's option 82
field.
Enabled – When the field is toggled to Enable, the relay agent will check the validity of the
packet's option 82 field. If the switch receives a packet that contains the option-82 field from
a DHCP client, the switch drops the packet because it is invalid. In packets received from
DHCP servers, the relay agent will drop invalid messages.
Disabled - When the field is toggled to Disabled, the relay agent will not check the validity of
the packet's option 82 field.
This field can be toggled between Replace, Drop, and Keep by using the pull-down menu.
It is used to set the Switches policy for handling packets when the DHCP Agent
Information Option 82 Check is set to Disabled. The default is Replace.
Replace - The option 82 field will be replaced if the option 82 field already exists in the
packet received from the DHCP client.
Drop - The packet will be dropped if the option 82 field already exists in the packet received
from the DHCP client.
Keep -The option 82 field will be retained if the option 82 field already exists in the packet
received from the DHCP client.
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