3Com 4500 PWR 26-Port Configuration Manual page 508

[Switch-Ethernet1/0/3] dhcp-s
IP Fil tering Configuration Example
N etwork requirements
As shown in Figure
Ethernet 1/0/2 is connected to H
0001-0001-0001 respectively. Ethernet 1/0/3 and Ethernet 1/0/4
Client C.
Enable DHCP snooping on the switch, and specify Ethernet 1/0/1 as the DHCP snooping trusted
port.
Enable IP filtering on Ethernet 1/0/2, Ethernet 1/0/3, and Ethernet 1/0/4 to prevent attacks to the
server from clients using fake source IP addresses.
Create static binding entries on the switch, so that Host A using a fixed IP address can access
external networks.
Network diagram
Figure 41-7 Network diagram for IP filtering configuration
Configuration procedure
# Enable DHCP snooping on the switch.
<Switch> system-view
[Switch] dhcp-snooping
# Specify Ethernet 1/0/1 as the trusted port.
[Switch] interface ethernet 1/0/1
[Switch-Ethernet1/0/1] dhcp-snooping trust
[Switch-Ethernet1/0/1] quit
# Enable IP filtering on Ethernet 1/0/2, Ethernet 1/0/3, and Ethernet 1/0/4 to filter packets based on the
source IP addresses/MAC addresses.
[Switch] interface ethernet 1/0/2
[Switch-Ethernet1/0/2] ip check source ip-address mac-address
nooping information vlan 1 circuit-id string abcd
41-7, Ethernet 1/0/1 of the S4500 switch is connected to the DHCP server and
ost A. The IP address and MAC address of Host A are 1.1.1.1 and
are connected to DHCP Client B and
41-12