xStack DES-3800 Series Layer 3 Stackable Fast Ethernet Managed Switch CLI Manual
145
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 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 d
isable
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.
Restrictions Only
administrator-level users can issue this command.
Example usage:
To configure DHCP relay option 82 state:
DES-3800:4#config dhcp_relay option_82 state enable
Command: config dhcp_relay option_82 state enable
Success.
DES-3800:4#
