H3C S3100 Series

3-13
DHCP Snooping Configuration Example
DHCP-Snooping Option 82 Support Configuration Example
Network requirements
As shown in Figure 3-8, Ethernet1/0/5 of the switch (S3100-EI) is connected to the DHCP server, and
Ethernet1/0/1, Ethernet1/0/2, and Ethernet1/0/3 are respectively connected to Client A, Client B, and
Client C.
z Enable DHCP snooping on the switch.
z Specify Ethernet1/0/5 on the switch as a trusted port for DHCP snooping.
z Enable DHCP-snooping Option 82 support on the switch and set the remote ID field in Option 82 to
the system name of the switch. Set the circuit ID sub-option to “abcd” in DHCP packets from VLAN
1 on Ethernet 1/0/3.
Network diagram
Figure 3-8 Network diagram for DHCP-snooping Option 82 support configuration
Eth1/0/2
Client B
Switch
DHCP Snooping
Client A
Eth1/0/1
Client C
Eth1/0/3
Eth1/0/5
DHCP Server
Configuration procedure
# Enable DHCP snooping on the switch.
<Switch> system-view
[Switch] dhcp-snooping
# Specify Ethernet1/0/5 as the trusted port.
[Switch] interface Ethernet1/0/5
[Switch-Ethernet1/0/5] dhcp-snooping trust
[Switch-Ethernet1/0/5] quit
# Enable DHCP-snooping Option 82 support.
[Switch] dhcp-snooping information enable
# Set the remote ID sub-option in Option 82 to the system name (sysname) of the DHCP snooping
device.
[Switch] dhcp-snooping information remote-id sysname