D-Link DGS-3700

DGS-3700-12/DGS-3700-12G Series Layer 2 Gigabit Ethernet Switch User Manual

DHCP relay information (option 82 field) in messages between DHCP servers and cli ents,

and the check and policy settings will have no effect.

DHCP Relay Agent

Information Option 82

Check

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 valid ity of t he pack et’s opt ion 82

field.

Enabled – When the field is toggled to Enable, t he relay agent will check the vali dity of the

packet’s option 82 field. If the switch receives a packet that cont ai ns the op tio n-8 2 f iel d f rom

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 D isabled, the relay agent will not check the validity

of the packet’s option 82 field.

DHCP Relay Agent

Information Option 82

Policy

This field can be toggled between Replace, Drop, and Keep by usin g the pull-do w n m enu. 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 pack et r ec eive d

from the DHCP client.

Keep – The option 82 field will be retained if the optio n 82 field alread y exists in the pac ket

received from the DHCP client.

DHCP Relay Option

60 State This function enables or disables the DHCP option 60 state. W hen option 60 is enabl ed, if

the packet does not have option 60, then the relay servers cannot be determined based on

option 60. The relay servers will be determined based on either opt ion 60 or per IPIF

configured servers. If the relay servers are determined based on option 60, the n the IPIF

configured servers will be ignored. If the relay servers are not d eterm ined b y option 60 t hen

the IPIF configured servers will be used to determine the relay servers.

DHCP Relay Option

61 State This function enables or disables the DHCP option 61 state. W hen option 61 is enab led, if

the packet does not have option 61, then the relay servers cannot be determined based on

option 61. The relay servers will be determined based on opti on 61 and the IPIF conf igured

servers will be ignored. If the relay servers are not determined either by option 60 or optio n

61, then IPIF configured servers will be used to determine the relay ser vers.

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 cl ient and the

information-checking feature is enabled, the switch drops the packet because it i s 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 rem ove the option-82 field from the

packet. You can configure the action that the switch tak es when it receives a packet with existing

option-82 information by configuring the DHCP Agent Information Option 82 Policy.