H3C Technologies H3C S5120 Series Switches - Manual (Page 260)

3-7
To do… Use the command… Remarks
Clear DHCP snooping entries
reset dhcp-snooping { all | ip
ip-address }
Available in user view
Clear DHCP packet statistics on the
DHCP snooping device reset dhcp-snooping packet
statistics
Available in user view
DHCP Snooping Configuration Examples
DHCP Snooping Configuration Example
Network requirements
As shown in Figure 3-3 , Switch A is connected to a DHCP server through GigabitEthernet 1/0/1, and to
two DHCP clients through GigabitEthernet 1/0/2 and GigabitEthernet 1/0/3. GigabitEthernet 1/0/1
forwards DHCP server responses while the other two do not.
Switch A records clients’ IP-to-MAC address bindings in DHCP-REQUEST messages and DHCP-ACK
messages received from trusted ports.
Figure 3-3 Network diagram for DHCP snooping configuration
Configuration procedure
# Enable DHCP snooping.
<SwitchA> system-view
[SwitchA] dhcp-snooping
# Specify GigabitEthernet1/0/1 as trusted.
[SwitchA] interface GigabitEthernet 1/0/1
[SwitchA-GigabitEthernet1/0/1] dhcp-snooping trust
[SwitchA-GigabitEthernet1/0/1] quit
DHCP Snooping Option 82 Support Configuration Example
Network requirements
z As shown in Figure 3-3 , enable DHCP snooping and Option 82 support on Switch A.
z Configure the handling strategy for DHCP requests containing Option 82 as replace.