Safeguard Engine Settings - D-Link DES-3528 - xStack Switch - Stackable Reference Manual

xStack® DES-3528/DES-3552 Series Layer 2 Stackable Fast Ethernet Managed Switch Web UI Reference Guide
When the user clicks the Edit button, one will be able to edit the service allowed to the selected host.
The fields that can be configured are described below:
Parameter
IPv4 Address
IPv6 Address
Net Mask
Access Interface
Click the Add button to add a new entry based on the information entered.
Click the Delete All button to remove all the entries listed.

Safeguard Engine Settings

Periodically, malicious hosts on the network will attack the switch by utilizing packet flooding (ARP Storm) or other
methods. These attacks may increase the switch load beyond its capability. To alleviate this problem, the Safeguard
Engine function was added to the Switch's software.
The Safeguard Engine can help the overall operability of the Switch by minimizing the workload of the Switch while the
attack is ongoing, thus making it capable to forward essential packets over its network in a limited bandwidth. The
Safeguard Engine has two operating modes that can be configured by the user, Strict and Fuzzy. In Strict mode, when
the Switch either (a) receives too many packets to process or (b) exerts too much memory, it will enter the Exhausted
mode. When in this mode, the Switch will drop all ARP and IP broadcast packets and packets from un-trusted IP
addresses for a calculated time interval. Every five seconds, the Safeguard Engine will check to see if there are too
many packets flooding the Switch. If the threshold has been crossed, the Switch will initially stop all ingress ARP and
IP broadcast packets and packets from un-trusted IP addresses for five seconds. After another five-second checking
interval arrives, the Switch will again check the ingress flow of packets. If the flooding has stopped, the Switch will
again begin accepting all packets. Yet, if the checking shows that there continues to be too many packets flooding the
Switch, it will stop accepting all ARP and IP broadcast packets and packets from un-trusted IP addresses for double
the time of the previous stop period. This doubling of time for stopping these packets will continue until the maximum
time has been reached, which is 320 seconds and every stop from this point until a return to normal ingress flow would
be 320 seconds. For a better understanding, please examine the following example of the Safeguard Engine.
Description
Enter an IPv4 address to add to the trusted host list.
Enter an IPv6 address to add to the trusted host list.
Enter a Net Mask address to add to the trusted host list.
Tick the check boxes to select services that will be allowed to the trusted host.
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