Barox Kommunikation RY-LGSP23-10G, User Manual, Page: 40 / 383

barox Kommunikation
Publication date: Sept, 2015
Revision A1
29
2-4.3 Relay
A DHCP relay agent is used to forward and to transfer DHCP messages
between the clients and the server when they are not in the same subnet
domain. It stores the incoming interface IP address in the GIADDR field of the
DHCP packet. The DHCP server can use the value of GIADDR field to determine
the assigned subnet. For such condition, please make sure the switch
configuration of VLAN interface IP address and PVID(Port VLAN ID) correctly.
Web Interface
To configure DHCP Relay in the web interface:
1.
Click Configuration, DHCP, Relay
2. Specify the Relay Mode, Relay server, Relay Information Mode, Relay Information police.
3. Click Apply.
Figure 2-4.3: The DHCP Relay Configuration
Parameter description:

Relay Mode :
Indicates the DHCP relay mode operation.
Possible modes are:
Enabled: Enable DHCP relay mode operation. When DHCP relay mode operation is enabled,
the agent forwards and transfers DHCP messages between the clients and the server when
they are not in the same subnet domain. And the DHCP broadcast message won't be
flooded for security considerations.
Disabled: Disable DHCP relay mode operation.

Relay Server
Indicates the DHCP relay server IP address.

Relay Information Mode
Indicates the DHCP relay information mode option operation. The option 82 circuit ID
format as "[vlan_id][module_id][port_no]". The first four characters represent the VLAN ID,
the fifth and sixth characters are the module ID(in standalone device it always equal 0, in
stackable device it means switch ID), and the last two characters are the port number. For
example, "00030108" means the DHCP message receive form VLAN ID 3, switch ID 1, port
No 8. And the option 82 remote ID value is equal the switch MAC address.