Dhcp Server Screening; Dhcp Screening Port Settings; Dhcp Offer Filtering - D-Link DGS-3200-16 - Switch - Stackable User Manual

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DHCP Server Screening

The DHCP Server Screening folder contains two windows: DHCP Screening Port Settings and DHCP Offer Filtering.

DHCP Screening Port Settings

The Switch supports DHCP Server Screening, a feature that denies access to rogue DHCP servers.
When the DHCP server filter function is enabled, all DHCP server packets will be filtered from a specific port.
To view the following window, click Security > DHCP Server Screening > DHCP Screening Port Settings:
The user may set the following parameters:
Parameter
From DHCP Server
Trap Log State
Illegal Server Log
Suppress Duration
From Port/To Port
State
After setting the previous parameters, click Apply to allow your changes to be implemented.

DHCP Offer Filtering

This function allows the user to not only restrict all DHCP Server packets but also to receive any specified DHCP server packet by
any specified DHCP client, it is useful when one or more DHCP servers are present on the network and both provide DHCP
services to different distinct groups of clients. The first time the DHCP filter is enabled it will create both an access profile entry
and an access rule per port entry, it will also create other access rules. These rules are used to block all DHCP server packets. In
addition to a permit DHCP entry, it will also create one access profile and one access rule entry the first time the DHCP client
MAC address is used as the client MAC address. The Source IP address is the same as the DHCP server's IP address (UDP source
port number 67). These rules are used to permit the DHCP server packets with specific fields, which the user has configured.
To view the following window, click Security > DHCP Server Screening > DHCP Offer Filtering:
®
DGS-3200 Series Layer 2 Gigabit Ethernet Managed Switch
Figure 5 - 11. DHCP Screening Port Settings window
Description
Enable or disable this feature.
Choose an illegal server log suppress duration of 1 minute, 5 minutes, or 30 minutes.
A consecutive group of ports may be configured starting with the selected port.
Choose Enabled to enable the DHCP server screening or Disabled to disable it. The default
is Disabled.
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