2-4.2 Snooping - OTS ET42202M-S-PD User Manual

ET42202M-S-PD
L2+ Managed 20-port 100Base-FX/1000Base-X SFP + 4-port 10/100/1000Base-T or
100/1000Base-FX SFP Combo Optical Ethernet Switch with AC + DC inputs

2-4.2 Snooping

DHCP Snooping is used to block intruder on the untrusted ports of the switch device when it
tries to intervene by injecting a bogus DHCP reply packet to a legitimate conversation between
the DHCP client and server.
The section describes to configure the DHCP Snooping parameters of the switch. The DHCP
Snooping can prevent attackers from adding their own DHCP servers to the network.
Web Interface
To configure DHCP snooping in the web interface:
1. Click Configuration, DHCP, Snooping
2. Select "Enabled" in the Mode of DHCP Snooping Configuration.
3. Select "Trusted" of the specific port in the Mode of Port Mode Configuration.
4. Click Apply.
Figure 2-4.2: The DHCP Snooping Configuration
Parameter description:
Snooping Mode :
Indicates the DHCP snooping mode operation. Possible modes are:
Enabled: Enable DHCP snooping mode operation. When DHCP snooping mode
operation is enabled, the DHCP request messages will be forwarded to trusted
ports and only allow reply packets from trusted ports.
Disabled: Disable DHCP snooping mode operation.
Port Mode Configuration
Indicates the DHCP snooping port mode. Possible port modes are:
Trusted: Configures the port as trusted source of the DHCP messages.
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