SMC Networks 6128L2, Management Manual

Page: 576 / 606

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• When the DHCP Snooping Information Option is enabled, clients
can be identified by the switch port to which they are connected rather
than just their MAC address. DHCP client-server exchange messages
are then forwarded directly between the server and client without
having to flood them to the entire VLAN.
• DHCP snooping must be enabled on the switch for the DHCP
Option 82 information to be inserted into packets.
Example
This example enables the DHCP Snooping Information Option.
ip dhcp snooping information policy
This command sets the DHCP snooping information option policy for
DHCP client packets that include Option 82 information.
Syntax
ip dhcp snooping information policy <drop | keep | replace>
• drop - Discards all DHCP client packets with Option 82
information.
• keep - Retains the client’s DHCP information
• replace - Overwrites the DHCP client packet information with the
switch’s relay information.
Default Setting
replace
Command Mode
Global Configuration
Command Usage
When the switch receives DHCP packets from clients that already
include DHCP Option 82 information, the switch can be configured to
set the action policy for these packets. Either the switch can drop the
DHCP packets, keep the existing information, or replace it with the
switch’s relay information.
Console(config)#ip dhcp snooping information option
Console(config)#