PLANET SGSW-24040 - Manual (Page 75)

User’s Manual of SGSW-24040 / 24240 Series
75
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 Relay
Configuration screen in Figure 4-2-11 appears.
Figure 4-2-11 DHCP Relay Configuration page screenshot
The page includes the following fields:
Object Description
• Relay Mode
Indicates the DHCP relay mode operation. Possible modes are:
Enabled: Enable DHCP relay mode operation. When enable DHCP relay mode
operation, the agent forward and to transfer DHCP messages between the
clients and the server when they are not on the same subnet domain. And the
DHCP broadcast message won't flood for security considered.
Disabled: Disable DHCP relay mode operation.
• Relay Server
Indicates the DHCP relay server IP address. A DHCP relay agent is used to
forward and to transfer DHCP messages between the clients and the server
when they are not on the same subnet domain.
• Relay Information
Mode
Indicates the DHCP relay information mode option operation. Possible modes
are:
Enabled: Enable DHCP relay information mode operation. When enable DHCP
relay information mode operation, the agent insert specific information (option
82) into a DHCP message when forwarding to DHCP server and remove it from a
DHCP message when transferring to DHCP client. It only works under DHCP
relay operation mode enabled.
Disabled: Disable DHCP relay information mode operation.
• Relay Information
Policy
Indicates the DHCP relay information option policy. When enable DHCP relay
information mode operation, if agent receive a DHCP message that already
contains relay agent information. It will enforce the policy. And it only works under