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DHCP snooping configuration examples
Example: Configuring basic DHCP snooping
Network configuration
, Switch B is connected to the authorized DHCP server through
GigabitEthernet 1/0/1, to the unauthorized DHCP server through GigabitEthernet 1/0/3, and to the
DHCP client through GigabitEthernet 1/0/2.
Configure only the port connected to the authorized DHCP server to forward the responses from the
DHCP server. Enable the DHCP snooping device to record clients' IP-to-MAC bindings by reading
DHCP-ACK messages received from the trusted port and the DHCP-REQUEST messages.
Figure 47 Network diagram
Procedure
# Enable DHCP snooping.
<SwitchB> system-view
[SwitchB] dhcp snooping enable
# Configure GigabitEthernet 1/0/1 as a trusted port.
[SwitchB] interface gigabitethernet 1/0/1
[SwitchB-GigabitEthernet1/0/1] dhcp snooping trust
[SwitchB-GigabitEthernet1/0/1] quit
# Enable recording clients' IP-to-MAC bindings on GigabitEthernet 1/0/2.
[SwitchB] interface gigabitethernet 1/0/2
[SwitchB-GigabitEthernet1/0/2] dhcp snooping binding record
[SwitchB-GigabitEthernet1/0/2] quit
Verifying the configuration
# Verify that the DHCP client can obtain an IP address and other configuration parameters only from
the authorized DHCP server. (Details not shown.)
# Display the DHCP snooping entry recorded for the client.
[SwitchB] display dhcp snooping binding