H3C Technologies H3C S12500 Series Switches - Manual (Page 97)

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DHCP snooping configuration examples
IMPORTANT:
By default, Ethernet, VLAN, and aggregate interfaces are down. To configure such an interface, bring the
interface up by executing the undo shutdown command.
DHCP snooping configuration example
Network requirements
As shown in Figure 37 , Switch B is connected to a DHCP server through GigabitEthernet 3/0/1, and to
two DHCP clients through GigabitEthernet 3/0/2 and GigabitEthernet 3/0/3. GigabitEthernet 3/0/1
forwards DHCP server responses but the other two do not.
Switch B records clients' IP-to-MAC address bindings in DHCP-REQUEST messages and DHCP-ACK
messages received from trusted ports.
Figure 37 Network diagram
Configuration procedure
# Enable DHCP snooping.
<SwitchB> system-view
[SwitchB] dhcp-snooping
# Specify GigabitEthernet 3/0/1 as trusted.
[SwitchB] interface GigabitEthernet 3/0/1
[SwitchB-GigabitEthernet3/0/1] dhcp-snooping trust
[SwitchB-GigabitEthernet3/0/1] quit
DHCP snooping Option 82 support configuration example
Network requirements
As shown in Figure 37 , DHCP snooping and Option 82 support are enabled on Switch B. The handling
strategy for DHCP requests containing Option 82 is configured as replace.
On GigabitEthernet 3/0/2, configure the padding content for the circuit ID sub-option as company001
and for the remote ID sub-option as device001. On GigabitEthernet 3/0/3, configure the padding