TP-Link T1500 Series User Manual page 709

Configuring DHCP Filter
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Note:
The member port of an LAG (Link Aggregation Group) follows the configuration of the LAG and not
its own. The configurations of the port can take effect only after it leaves the LAG.
The following example shows how to enable DHCPv4 Filter globally and how to enable
DHCPv4 Filter, enable the MAC verify feature, set the limit rate as 10 pps and set the
decline rate as 20 pps on port 1/0/1:
interface { fastEthernet port | range fastEthernet port-list | gigabitEthernet port | range
gigabitEthernet port-list | ten-gigabitEthernet port | range ten-gigabitEthernet port-list |
interface port-channel port-channel-id | interface range port-channel port-channel-id-list }
Enter interface configuration mode.
ip dhcp filter
Enable DHCPv4 Filter on the port.
ip dhcp filter mac-verify
Enable the MAC Verify feature. There are two fields in the DHCP packet that contain the
MAC address of the host. The MAC Verify feature compares the two fields of a DHCP
packet and discards the packet if the two fields are different. This prevents the IP address
resource on the DHCP server from being exhausted by forged MAC addresses.
ip dhcp filter limit rate value
Enable the limit rate feature and specify the maximum number of DHCP messages that can
be forwarded on the port per second. The excessive DHCP packets will be discarded.
Specify the limit rate value. The following options are provided: 0, 5,10,15,20,25 and
value:
30 (packets/second). The default value is 0, which indicates disabling limit rate.
ip dhcp filter decline rate value
Enable the decline protect feature and specify the maximum number of Decline packets
can be forwarded per second on the port. The excessive Decline packets will be discarded.
Specify the limit rate value of Decline packets. The following options are provided: 0,
value:
5,10,15,20,25 and 30 (packets/second). The default value is 0, which indicates disabling this
feature.
show ip dhcp filter
Verify the global DHCPv4 Filter configuration.
show ip dhcp filter interface [ fastEthernet port | gigabitEthernet port | ten-
gigabitEthernet port | port-channel port-channel-id ]
Verify the DHCPv4 Filter configuration of the port.
end
Return to privileged EXEC mode.
copy running-config startup-config
Save the settings in the configuration file.
DHCPv4 Filter Configuration
Configuration Guide 687