IGPS-9080 Series User Manual
ORing Industrial Networking Corp
49
5.2.4 Relay Agent
DHCP relay is used to forward and transfer DHCP messages between the clients and the
server when they are not in the same subnet domain. You can configure the function in this
page.
Label
Description
Relay Mode
Indicates the existing DHCP relay mode. The modes include:
Enabled
: activate DHCP relay. When DHCP relay is enabled, the
agent forwards and transfers DHCP messages between the clients
and the server when they are not in the same subnet domain to
prevent the DHCP broadcast message from flooding for security
considerations.
Disabled
: disable DHCP relay
Relay Server
Indicates the DHCP relay server IP address. A DHCP relay agent is
used to forward and transfer DHCP messages between the clients
and the server when they are not in the same subnet domain.
Relay Information
Mode
Indicates the existing DHCP relay information mode. The format of
DHCP option 82 circuit ID format is "[vlan_id][module_id][port_no]".
The first four characters represent the VLAN ID, and the fifth and
sixth characters are the module ID. In stand-alone devices, the
module ID always equals to 0; in stacked devices, it means switch
ID. The last two characters are the port number. For example,
"00030108" means the DHCP message received form VLAN ID 3,
switch ID 1, and port No. 8. The option 82 remote ID value equals
to the switch MAC address.
The modes include:
Enabled
: activate DHCP relay information. When DHCP relay
information is enabled, the agent inserts specific information
(option 82) into a DHCP message when forwarding to a DHCP
server and removes it from a DHCP message when transferring to