Huawei S Series Quick Configuration page 42

b. Configure DHCP snooping and IPSG.
User devices can automatically obtain IP addresses after DHCP is configured. If a
user connects a small router to the intranet and enable the DHCP server on the router,
authorized intranet users may obtain IP addresses allocated by the small router and
cannot access the Internet. To prevent this problem, configure DHCP snooping.
Department A is used in the example below.
1 Enable DHCP snooping on ACC1.
<ACC1> system-view
[ACC1] dhcp enable
[ACC1] dhcp snooping enable
2
Configure DHCP snooping on interfaces connecting to user devices.
[ACC1] interface GigabitEthernet 0/0/1
connecting to user devices in department A.
[ACC1-GigabitEthernet0/0/1] dhcp snooping enable
[ACC1-GigabitEthernet0/0/1] quit
[ACC1] interface GigabitEthernet 0/0/2
connecting to user devices in department B.
[ACC1-GigabitEthernet0/0/2] dhcp snooping enable
[ACC1-GigabitEthernet0/0/2] quit
Enable DHCP snooping on interfaces connecting to DHCP servers and configure the
3
interfaces as trusted interfaces.
[ACC1] interface GigabitEthernet 0/0/3
CORE1.
[ACC1-GigabitEthernet0/0/3] dhcp snooping enable
[ACC1-GigabitEthernet0/0/3] dhcp snooping trusted
trusted interface.
[ACC1-GigabitEthernet0/0/3] quit
[ACC1] interface GigabitEthernet 0/0/4
to CORE2.
[ACC1-GigabitEthernet0/0/4] dhcp snooping enable
[ACC1-GigabitEthernet0/0/4] dhcp snooping trusted
[ACC1-GigabitEthernet0/0/4] quit
After the preceding configuration is complete, user devices in department A can
obtain IP addresses from only the authorized DHCP server, and will not use IP
addresses allocated by the small router.
//Enable DHCP.
//Enable DHCP snooping.
//Configure the interface
//Configure the interface
//Configure the interface connecting to
//Enable DHCP snooping.
//Configure the interface as a
//Configure the interface connecting
39