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DES-3810 Series Layer 3 Managed Ethernet Switch Web UI Reference Guide
355
Parameter
Description
IPv4 Address
Here the user can enter an IPv4 address to add to the trusted host list.
Net Mask
Here the user can enter a IPv4 Net Mask address to add to the trusted host list.
IPv6 Address
Here the user can enter an IPv6 address to add to the trusted host list.
Net Mask
Here the user can enter a IPv6 Net Mask address to add to the trusted host list.
Access Interface
Here the user can select services that will be allowed to the trusted host.
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.
Click the
Edit
button to re-configure the specified entry.
Click the
Delete
button to remove the specified entry.
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.
Figure 9-86 Safeguard Engine window
For every consecutive checking interval that reveals a packet flooding issue, the Switch will double the time it will
discard ingress ARP and IP broadcast packets and packets from the illegal IP addresses. In the example above, the
Switch doubled the time for dropping ARP and IP broadcast packets when consecutive flooding issues were detected
Summary of Contents for xStack DES-3810
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