D-Link DES-1228/ME Reference Manual page 191

config dhcp_relay option_82 state
Purpose
Syntax
Description
Parameters
Restrictions
Example usage:
To configure DHCP relay option 82 state:
DES-1228/ME:5#config dhcp_relay option_82 state enable
Command: config dhcp_relay option_82 state enable
Success.
DES-1228/ME:5#
config dhcp_relay option_82 check
Purpose
Syntax
Description
Parameters
Restrictions
DES-1228/ME Metro Ethernet Managed Switch CLI Reference Guide
Used to configure the state of DHCP relay agent information option 82 of
the Switch.
config dhcp_relay option_82 state [enable | disable]
This command is used to configure the state of DHCP relay agent
information option 82 of the Switch.
enable − When this field is toggled to Enabled the relay agent will insert
and remove DHCP relay information (option 82 field) in messages
between DHCP server and client. When the relay agent receives the
DHCP request, it adds the option 82 information, and the IP address of
the relay agent (if the relay agent is configured), to the packet. Once the
option 82 information has been added to the packet it is sent on to the
DHCP server. When the DHCP server receives the packet, if the server
is capable of option 82, it can implement policies like restricting the
number of IP addresses that can be assigned to a single remote ID or
circuit ID. Then the DHCP server echoes the option 82 field in the DHCP
reply. The DHCP server unicasts the reply to the back to the relay agent
if the request was relayed to the server by the relay agent. The switch
verifies that it originally inserted the option 82 data. Finally, the relay
agent removes the option 82 field and forwards the packet to the switch
port that connects to the DHCP client that sent the DHCP request.
disable − If the field is toggled to disable the relay agent will not insert
and remove DHCP relay information (option 82 field) in messages
between DHCP servers and clients, and the check and policy settings will
have no effect.
Only Administrator level, Operator level or Power User level users can
issue this command.
Used to configure the checking mechanism of DHCP relay agent
information option 82 of the Switch.
config dhcp_relay option_82 check [enable | disable]
This command is used to configure the checking mechanism of
DHCP/BOOTP relay agent information option 82 of the Switch.
enable – When the field is toggled to enable, the relay agent will
check the validity of the packet's option 82 field. If the switch
receives a packet that contains the option 82 field from a DHCP
client, the switch drops the packet because it is invalid. In packets
received from DHCP servers, the relay agent will drop invalid
messages.
disable − When the field is toggled to disable, the relay agent will not
check the validity of the packet's option 82 field.
Only Administrator level, Operator level or Power User level users
can issue this command.
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