Common Operation (DHCP):Preventing a Device from Obtaining an IP Address from a

On the Layer 2 access device or the first DHCP relay device, configure DHCP snooping to prevent the device from obtaining an IP address from a pseudo DHCP server.

NOTE:

• For a Layer 2 access device, steps 1-3 are mandatory. Configure this function in sequence.

• For a DHCP relay device, only steps 1 and 2 are mandatory.

1. Enable DHCP snooping globally.

   <HUAWEI> system-view
   [HUAWEI] dhcp enable
   [HUAWEI] dhcp snooping enable

2. Enable DHCP snooping on the interface connected to the DHCP client (configuring all interfaces connected to the DHCP client and using GE1/0/1 as an example).

   [HUAWEI] interface gigabitethernet 1/0/1
   [HUAWEI-GigabitEthernet1/0/1] dhcp snooping enable
   [HUAWEI-GigabitEthernet1/0/1] quit

3. Configure the interface connected to the DHCP server as a trusted interface.

   [HUAWEI] interface gigabitethernet 1/0/2
   [HUAWEI-GigabitEthernet1/0/2] dhcp snooping trusted
   [HUAWEI-GigabitEthernet1/0/2] quit