Configuring Dhcp Snooping - H3C S3100-52P Operation Manual

Operation Manual – DHCP
H3C S3100-52P Ethernet Switch
device, and the number of the VLAN to which the port belongs to. These records are
saved as entries in the DHCP-snooping table.
II. IP static binding table
The DHCP-snooping table only records information about clients that obtains IP
address dynamically through DHCP. If a fixed IP address is configured for a client, the
IP address and MAC address of the client cannot be recorded in the DHCP-snooping
table. Consequently, this client cannot pass the IP filtering of the DHCP-snooping table,
thus it cannot access external networks.
To solve this problem, the switch supports the configuration of static binding table
entries, that is, the binding relationship between IP address, MAC address, and the port
connecting to the client, so that packets of the client can be correctly forwarded.
III. IP filtering
The switch can filter IP packets in the following two modes:
Filtering the source IP address in a packet. If the source IP address and the
number of the port that receives the packet are consistent with entries in the
DHCP-snooping table or static binding table, the switch regards the packet as a
valid packet and forwards it; otherwise, the switch drops it directly.
Filtering the source IP address and the source MAC address in a packet. If the
source IP address and source MAC address in the packet, and the number of the
port that receives the packet are consistent with entries in the DHCP-snooping
table or static binding table, the switch regards the packet as a valid packet and
forwards it; otherwise, the switch drops it directly.

2.2 Configuring DHCP Snooping

2.2.1 Configuring DHCP Snooping
Follow these steps to configure DHCP snooping:
Enter system view
Enable DHCP snooping
Enter Ethernet port view
To do...
system-view
dhcp-snooping
interface interface-type
interface-number
Chapter 2 DHCP Snooping Configuration
Use the command...
2-6
Remarks
—
Required
By default, the DHCP
snooping function is
disabled.
—