xStack DES-6500 Modular Layer 3 Chassis Ethernet Switch CLI Manual
config dhcp_relay option_82 state
Purpose
Used to configure the state of DHCP relay agent information option 82 of
the switch.
Syntax
config dhcp_relay option_82 state [enable | disable]
Description
This command is used to configure the state of DHCP relay agent
information option 82 of the switch.
Parameters
enable
- When
enabled,
the relay agent will insert and remove DHCP
relay information (option 82 field) in messages between DHCP servers
and clients. 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 and 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 packet. 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 is
connected to the DHCP client that sent the DHCP request.
disable -
If
disabled
the relay agent will not insert and remove DHCP
relay information (option 82 field) in messages between DHCP servers
and clients. In addition, the check and policy settings will have no effect.
Restrictions Only
administrator-level users can issue this command.
Example usage:
To configure DHCP relay option 82 state:
DES-6500:4#config dhcp_relay option_82 state enable
Command: config dhcp_relay option_82 state enable
Success.
DES-6500:4#
config dhcp_relay option_82 check
Purpose
Used to configure the checking mechanism of DHCP relay agent
information option 82 of the switch.
Syntax
config dhcp_relay option_82 check [enable | disable]
Description
This command is used to configure the checking mechanism of
DHCP/BOOTP relay agent information option 82 of the Switch.
Parameters
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.
Restrictions Only
administrator-level users can issue this command.
279
