Dhcp Relay Configuration - FibroLAN Falcon Gen-3 M-Class User Manual

Falcon M-Class | User Guide
5.2.6

DHCP Relay Configuration

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
Figure 5-12: DHCP Relay Configuration
Table 5-11: DHCP Relay Configuration Parameters
Relay Mode
Relay Server
Relay Information
Mode
Relay Information
Policy
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.
Indicates the DHCP relay server IP address.
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 receives form VLAN ID 3,
switch ID 1, port No 8. And the option 82 remote ID value is equal the
switch MAC address.
Possible modes are:
Enabled: Enable DHCP relay information mode operation. When DHCP
relay information mode operation is enabled, the agent inserts specific
information (option 82) into a DHCP message when forwarding to DHCP
server and removes it from a DHCP message when transferring to DHCP
client. It only works when DHCP relay operation mode is enabled.
Disabled: Disable DHCP relay information mode operation.
Indicates the DHCP relay information option policy. When DHCP relay
information mode operation is enabled, if agent receives a DHCP message
that already contains relay agent information it will enforce the policy.
And it only works under DHCP if relay information operation mode is
enabled. Possible policies are:
Replace: Replace the original relay information when a DHCP message
that already contains it is received.
Keep: Keep the original relay information when a DHCP message that
already contains it is received.
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