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DHCP
Relay
Configuration
Configure DHCP Relay on this page.
Relay Mode
Indicates the DHCP relay mode operation. Possible modes:
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. 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.
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 stand-alone device it always equal 0, in a stackable device it means
switch ID), and the last two characters are the port number. For example, "00030108" means the DHCP
message received from VLAN ID 3, switch ID 1, port No 8. And the option 82 remote ID value is equal to
the switch MAC address.
Possible modes:
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.
Relay Information Policy
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
:
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.
Drop:
Drop the
package
when a DHCP message that already contains relay information is received.
