xStack DGS-3400 Series Fast Ethernet Switch
Ping Test
Ping is a small program that sends ICMP Echo packets to the IP address you specify. The destination node then responds to
or "echoes" the packets sent from the Switch. This is very useful to verify connectivity between the Switch and other nodes
on the network.
Figure 6- 18. Ping Test window
The user may use Infinite times radio button, in the Repeat Pinging for field, which will tell the ping program to keep
sending ICMP Echo packets to the specified IP address until the program is stopped. The user may opt to choose a specific
number of times to ping the Target IP Address by clicking its radio button and entering a number between
1
and
255
. Click
Start
to initiate the Ping program.
Safeguard Engine
Periodically, malicious hosts on the network will attack the Switch by utilizing packet flooding (ARP Storm) or other
methods. These attacks may increase the CPU utilization beyond its capability. To alleviate this problem, the Safeguard
Engine function was added to the Switch’s software.
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. When the Switch
either (a) receives too many packets to process or (b) exerts too much memory, it will enter an
Exhausted
mode. When in
this mode, the Switch will perform the following tasks to mimimize the CPU usage:
1. It will limit bandwidth of receiving ARP packets. The user may implement this in two ways, by using the Mode
pull down menu in the screen below:
a. When
Strict
is chosen, the Switch will stop receiving ARP packets not destined for the Switch. This will
eliminate all unnecessary ARP packets while allowing the essential ARP packets to pass through to the
Switch’s CPU.
b. When
Fuzzy
is chosen, the Switch will mimimze the ARP packet bandwidth received by the switch by
adjusting the bandwidth for all ARP packets, whether destined for the Switch or not. The Switch uses an
internal algorithm to filter ARP packets through, with a higher percentage set aside for ARP packets
destined for the Switch.
2. It will limit the bandwidth of IP packets received by the Switch. The user may implement this in two ways, by
using the Mode pull down menu in the screen below:
a. When
Strict
is chosen, the Switch will stop receiving all unnecessary broadcast IP packets, even if the
high CPU utilization is not caused by the high receival rate of broadcast IP packets.
b. When
Fuzzy
is chosen, the Switch will mimimze the IP packet bandwidth received by the Switch by
adjusting the bandwidth for all IP packets, by setting a acceptable bandwidth for both unicast and
broadcast IP packets. The Switch uses an internal algorithm to filter IP packets through while adjusting
the bandwidth dynamically.
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Summary of Contents for xStack DGS-3427
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