Operation Manual – DHCP
H3C S5600 Series Ethernet Switches
Chapter 4 DHCP Snooping Configuration
4-12
To do…
Use the command…
Remarks
Create a static
binding
ip source static binding
ip-address ip-address
[
mac-address mac-address
]
Optional
By default, no static
binding entry is created.
Note:
z
Enable DHCP snooping and specify trusted ports on the switch before configuring
IP filtering.
z
You are not recommended to configure IP filtering on the ports of a fabric or an
aggregation group.
z
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.
z
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.
z
The VLAN ID of the IP static binding configured on a port is the VLAN ID of the port.
4.3 DHCP Snooping Configuration Examples
4.3.1 DHCP-Snooping Option 82 Support Configuration Example
I. Network requirements
As shown in
Figure 4-6
, GigabitEthernet 1/0/5 of the switch is connected to the DHCP
server, and GigabitEthernet 1/0/1, GigabitEthernet 1/0/2, and GigabitEthernet 1/0/3 are
respectively connected to Client A, Client B, and Client C.
z
Enable DHCP snooping on the switch.
z
Specify GigabitEthernet 1/0/5 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 GigabitEthernet 1/0/3.
