Dhcp Snooping Configuration Examples; Dhcp-Snooping Option 82 Support Configuration Example - H3C S3100-52P Operation Manual

Operation Manual – DHCP
H3C S3100-52P Ethernet Switch
Note:
Enable DHCP snooping and specify trusted ports on the switch before configuring
IP filtering.
You are not recommended to configure IP filtering on the ports of an aggregation
group.
To create a static binding after IP filtering is enabled with the mac-address keyword
specified on a port, the mac-address argument must be specified; otherwise, the
packets sent from this IP address cannot pass the IP filtering.
A static entry has a higher priority than the dynamic DHCP snooping entry that has
the same IP address as the static one. That is, if the static entry is configured after
the dynamic entry is recorded, the static entry overwrites the dynamic entry; if the
static entry is configured before DHCP snooping is enabled, no DHCP client can
obtain the IP address of the static entry, that is, the dynamic DHCP snooping entry
cannot be generated.
The VLAN ID of the IP static binding configured on a port is the VLAN ID of the port.

2.3 DHCP Snooping Configuration Examples

2.3.1 DHCP-Snooping Option 82 Support Configuration Example

I. Network requirements
As shown in
and Ethernet 1/0/1, Ethernet 1/0/2, and Ethernet 1/0/3 are respectively connected to
Client A, Client B, and Client C.
Enable DHCP snooping on the switch.
Specify Ethernet 1/0/5 on the switch as a trusted port for DHCP snooping.
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.
Figure 2-6, Ethernet 1/0/5 of the switch is connected to the DHCP server,
Chapter 2 DHCP Snooping Configuration
2-12