362
# Enable DHCP snooping.
<Device> system-view
[Device] dhcp-snooping
# Configure port GigabitEthernet 1/0/2, which is connected to the DHCP server, as a trusted
port.
[Device] interface gigabitethernet1/0/2
[Device-GigabitEthernet1/0/2] dhcp-snooping trust
[Device-GigabitEthernet1/0/2] quit
2.
Configure the IPv4 source guard function.
# Configure the IPv4 source guard function on port GigabitEthernet 1/0/1 to filter packets based
on both the source IP address and MAC address.
[Device] interface gigabitethernet1/0/1
[Device-GigabitEthernet1/0/1] ip verify source ip-address mac-address
[Device-GigabitEthernet1/0/1] quit
Verifying the configuration
# Display the IPv4 source guard entries generated on port GigabitEthernet 1/0/1.
[Device] display ip source binding
Total entries found: 1
MAC Address IP Address VLAN Interface Type
0001-0203-0406 192.168.0.1 1 GE1/0/1 DHCP-SNP
# Display DHCP snooping entries to see whether they are consistent with the dynamic entries generated
on GigabitEthernet 1/0/1.
[Device] display dhcp-snooping
DHCP snooping is enabled.
The client binding table for all untrusted ports.
Type : D--Dynamic , S--Static , R--Recovering
Type IP Address MAC Address Lease VLAN SVLAN Interface
==== =============== ============== ============ ==== ===== =================
D 192.168.0.1 0001-0203-0406 86335 1 N/A GigabitEthernet1/0/1
--- 1 dhcp-snooping item(s) found ---
The output shows that a dynamic IPv4 source guard entry has been generated based on the DHCP
snooping entry.
Dynamic IPv4 source guard using DHCP relay configuration
example
Network requirements
As shown in
, the host and the DHCP server are connected to the switch through interfaces
VLAN-interface 100 and VLAN-interface 200 respectively. DHCP relay is enabled on the switch. The host
(with the MAC address of 0001-0203-0406) obtains an IP address from the DHCP server through the
DHCP relay agent.
Enable the IPv4 source guard function on the switch’s VLAN-interface 100 to filter packets based on the
DHCP relay entry, allowing only packets from clients that obtain IP addresses from the DHCP server to
pass.