Interlogix NS3500-28T-4S, User Manual

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Figure 4-9-43
DHCP Rate Limit Setting Page Screenshot
The page includes the following fields:
Object Description

Port
The switch port number of the logical port.

Rate Limit (pps)
Display the current rate limit.
4.9.7.8 Option82 Global Setting
DHCP provides a relay mechanism for sending information about the switch and its DHCP clients to DHCP servers.
Known as
DHCP Option 82
, it allows compatible DHCP servers to use the information when assigning IP addresses,
or to set other services or policies for clients. It is also an effective tool in preventing malicious network attacks from
attached clients on DHCP services, such as IP Spoofing, Client Identifier Spoofing, MAC Address Spoofing, and
Address Exhaustion.
The
DHCP option 82
enables a DHCP relay agent to insert specific information into a DHCP request packets when
forwarding client DHCP packets to a DHCP server and remove the specific information from a DHCP reply packets
when forwarding server DHCP packets to a DHCP client. The DHCP server can use this information to implement IP
address or other assignment policies. Specifically the option works by setting two sub-options:
 Circuit ID (option 1)
 Remote ID (option2).
The Circuit ID sub-option is supposed to include information specific to which circuit the request came in on.
The Remote ID sub-option was designed to carry information relating to the remote host end of the circuit.