Security > Gratuitous Arp - D-Link DGS-1210-12TS/ME User Manual

4 Configuration
DGS-1210 series Metro Ethernet Managed Switch User Manual
Figure 4.132 – Security > CPU Protect
CPU Protect State: Specifies the CPU protect state to be enabled or disabled.
Click the Apply button to accept the changes made.
The CPU Protect Types are ARP, BPDU, ICMP, IGMP and SNMP. Select the CPU Protect Type and enter
the Rate limit which the value is between 0 and 65535 pps. The default value is no limit.
Click the Apply button to save your settings.
Security > Gratuitous ARP
The Gratuitous ARP page shows the settings on the Switch. An ARP announcement (also known as
Gratuitous ARP) is a packet (usually an ARP Request) containing a valid SHA (Sender Hardware Address)
and SPA (Sender Protocol Address) for the host which sent it, with TPA (Target Protocol Address) equal to
SPA. Such a request is not intended to solicit a reply, but merely update the ARP caches of other hosts
which receive the packet and determine if there are any IP conflicts.
Figure 4.133 – Security > Gratuitous ARP
Send when IP Interface is up: This is used to enable/disable the sending of gratuitous ARP request
packets while an IP interface comes up. This is used to automatically announce the interface's IP address to
other nodes. By default, the state is Disabled, and only one ARP packet will be broadcast.
Send when duplicated IP is detected: This is used to enable/disable the sending of gratuitous ARP
request packets while a duplicate IP is detected. By default, the state is Disabled. Duplicate IP detected
means that the system received an ARP request packet that is sent by an IP address that matches the
system's own IP address.
Learn received Gratuitous ARP: This is used to enable/disable updating ARP cache based on the received
gratuitous ARP packet. If a switch receives a gratuitous ARP packet and the sender's IP address in its ARP
table, it should update the ARP entry. This is Disabled by default.
Gratuitous ARP Send Interval: Specify the interval value.
Interface Name: Specify the Interface Name. The default is System.
Time Interval (0-65535): Specify the time interval, the range is from 0 to 65535, and the default is 0 seconds.
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