D-Link DWS-3160-24TC DWS-3160 Series Web UI Reference Guide - Page 272

DWS-3160 Series Gigabit Ethernet Unified Switch Web UI Reference Guide DHCP Relay Agent Information Option 82 Check DHCP Relay Agent Information Option 82 Policy DHCP Relay Agent Information Option 82 Remote ID DHCP Relay Option 60 State configured), to the packet. Once the option 82 information has been added to the packet it is sent on to the DHCP server. When the DHCP server receives the packet, if the server is capable of option 82, it can implement policies like restricting the number of IP addresses that can be assigned to a single remote ID or circuit ID. Then the DHCP server echoes the option 82 field in the DHCP reply. The DHCP server unicasts the reply back to the relay agent if the request was relayed to the server by the relay agent. The switch verifies that it originally inserted the option 82 data. Finally, the relay agent removes the option 82 field and forwards the packet to the switch port that connects to the DHCP client that sent the DHCP request. Disabled- When the field is toggled to Disabled, the relay agent will not insert and remove DHCP relay information (option 82 field) in messages between DHCP servers and clients, and the check and policy settings will have no effect. Use the drop-down menu 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 Enabled, 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. Use the drop-down menu to set the Switches policy for handling packets when the DHCP Relay 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. Enter the DHCP Relay Agent Information Option 82 Remote ID. Use the drop-down menu to enable or disable the use of the DHCP Relay Option 60 State feature. If the packet does not have option 60 enabled, then the relay servers cannot be determined based on the option 60. In this case the relay servers will be determined based on either option 61 or per IPIF configured servers. If the relay servers are determined based on option 60 or option 61, then per IPIF configured servers will be ignored. If the relay servers are not determined by either option 60 or option 61, then per IPIF configured servers will be used to determine the relay servers. enable - Select this option to enable the DHCP Relay Option 60 state, in order to relay DHCP packets. disable - Select this option to disable the DHCP Relay Option 60 state. DHCP Relay Option 61 State Use the drop-down menu to enable or disable the use of the DHCP Relay Option 61 State feature. When option 61 is enabled, if the packet does not have option 61, then the relay servers cannot be determined based on option 61. If the relay servers are determined based on option 60 or option 61, then per IPIF configured servers will be ignored. If the relay servers are not determined either by option 60 or option 61, then per IPIF configured servers will be used to determine the relay servers. enable - Select this option to enable the DHCP Relay Option 61 state, in order to relay DHCP packets. disable - Select this option to disable the DHCP Relay Option 61 state. Click the Apply button to accept the changes made for each individual section. 267