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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 this window, click Security > DHCP Server Screening > DHCP Screening Port Settings as shown below:
Figure 5 - 12 DHCP Screening Port Settings window
The following parameters can be set:
Parameter Description
From Port / To Port A consecutive group of ports may be configured starting with the selected port. | |
State | Choose Enabled to enable the DHCP server or Disabled to disable. The default is Disabled. |
After setting the previous parameters, click Apply to allow your changes to be implemented. The DHCP Port Information Table shows which ports are enabled or disabled for DHCP Sever Screening.
DHCP Offer Filtering
This function allows the user not only to 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 this window, click Security > DHCP Server Screening > DHCP Offer Filtering as shown below:
Figure 5 - 13 DHCP Offer Filtering window
The user may set the following parameters:
ParameterDescription
Server IP Address
The IP address of the DHCP server.
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