H3C LS-5100-16P-SI-OVS-H3 Configuration page 22

DHCP
H3C Low-End Ethernet Switches Configuration Examples
For example, the DHCP messages from clients connected to Ethernet1/0/11 are added
with Option 82, whose Circuit ID suboption should be 0x010600040001000a, where
01060004 is a fixed value, 0001 indicates the access port's VLAN is VLAN 1, and 000a
is the absolute number of the port, which is 1 less than the actual port number,
indicating the actual port is Ethernet1/0/11.
Remote ID suboption: It identifies the MAC address of the DHCP snooping device
connected to the client.
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Type(2)
Figure 2-7 Packet structure of Remote ID suboption
For example, the DHCP messages from clients connected to the DHCP snooping
device with MAC 000f-e234-bc66 are added with Option 82, whose Remote ID
suboption should be 02080006000fe234bc66, where 02080006 is a fixed value and
000fe234bc66 is the MAC address of the DHCP snooping device.
In this example, IP addresses are assigned based on port number only. Therefore, on
the DHCP server, only a matching port number field in the Circuit ID suboption needs to
be found.
Note:
The following configuration is performed on the Cisco Catalyst 3745 switch running IOS
version 12.3(11)T2. If you are using any other models or devices running any other
version, see the user manuals provided with the devices.
# Enable DHCP server and allocate IP addresses using Option 82 information.
Switch> enable
Switch(config)# configure terminal
Enter Configuration commands, one per line. End with CNTL/Z.
Switch(config)# service dhcp
Switch(config)# ip dhcp use class
# Create a DHCP class for the client connected to Ethernet1/0/11 of the DHCP
snooping device and match the port number in the Circuit ID suboption of Option82,
and replace the contents without match need with a wildcard "*".
Switch(config)# ip dhcp class office1
Switch(dhcp-class)# relay agent information hex 010600040001000a*
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Bridge MAC Address
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