Planet WGSW-28040 User Manual page 184

client DHCP packets to a DHCP server and remove the specific information from a DHCP reply packets when forwarding server
DHCP packets to a DHCP client. The DHCP server can use this information to implement IP address or other assignment
policies. Specifically the option works by setting two sub-options:
 Circuit ID (option 1)
 Remote ID (option2).
The Circuit ID sub-option is supposed to include information specific to which circuit the request came in on.
The Remote ID sub-option was designed to carry information relating to the remote host end of the circuit.
The definition of Circuit ID in the switch is 4 bytes in length and the format is "vlan_id" "module_id" "port_no". The parameter of
"vlan_id" is the first two bytes represent the VLAN ID. The parameter of "module_id" is the third byte for the module ID (in
standalone switch it always equal 0, in stackable switch it means switch ID). The parameter of "port_no" is the fourth byte and it
means the port number.
The Remote ID is 6 bytes in length, and the value is equal the DHCP relay agent's MAC address. The DHCP Snooping Port
Option82 Setting screen in
The page includes the following fields:
Object
• Port
• Enable
• Action
Figure 4-10-6 appears.
Figure 4-10-6 DHCP Snooping Port Option82 Setting page screenshot
Description
Select port for this drop down list.
Enables or disables DHCP Option 82 information relay.
(Default: Disabled)
Sets the DHCP snooping information option policy for DHCP client packets that
include Option 82 information.
• Drop
• Keep
User's Manual of WGSW-28040 / 28040P / 28040P4
Discards the Option 82 information in a packet and then floods it to
the entire VLAN.
Retain the Option 82 information in the client request, insert the
relay agent's address (when DHCP snooping is enabled), and
unicast the packet to the DHCP server.
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