4-10To do… Use the command… RemarksCreate a static bindingip source static binding ip-addressip-address [ mac-addressmac-address ]OptionalBy default, no static bindingentry is created.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 aport, the mac-address argument must be specified; otherwise, the packets sent from this IPaddress cannot pass the IP filtering.z A static entry has a higher priority than the dynamic DHCP snooping entry that has the same IPaddress as the static one. That is, if the static entry is configured after the dynamic entry isrecorded, the static entry overwrites the dynamic entry; if the static entry is configured beforeDHCP 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.DHCP Snooping Configuration ExamplesDHCP-Snooping Option 82 Support Configuration ExampleNetwork requirementsAs shown in Figure 4-6 GigabitEthernet 1/0/5 of the switch is connected to the DHCP server, andGigabitEthernet 1/0/1, GigabitEthernet 1/0/2, and GigabitEthernet 1/0/3 are respectively connected toClient 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 tothe system name of the switch. Set the circuit ID sub-option to abcd in DHCP packets from VLAN1 on GigabitEthernet 1/0/3.
