DGS-3700-12/DGS-3700-12G Series Layer 2 Gigabit Ethernet Switch User Manual
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Rate (64-1024000) This field allows you to enter the data rate, in Kbits per second, that will be the limit for the
selected port. The value must be a multiple of 64, between 64 and 1024000.
Click Apply to set t he bandwidth control for the selected ports. Results of configured Bandwidth Settings will be
displayed in the Bandwidth Control Table on the lower half of the window.
On a computer network, packets such as Multicast packets and Br oadcast packets continua lly flood the network as
normal procedure. At times, this traffic may increase due to a m alicious endst ation on th e net work or a m alf unctioning
device, such as a faulty network card. Thus, switch throughput problems will arise and consequen tly aff ect the overal l
performance of the switch network. To help rectify this packet storm, the S witch will monitor and control the situation.
The packet storm is monitored to determine if too many packets are flooding the net work , bas ed on th e thr es hold level
provided by the user. Once a packet storm has been detected, the Switc h will drop packets coming into the Switch
until the storm has subsided. This method can be utilized by selecting the Drop option of the A ction field in the window
below.
The Switch will also scan and monitor packets coming into th e Switch by monit oring the Switch’s chip counter. This
method is only viable for Broadcast and Multicast storms because the chip on ly has counters for thes e two types of
packets. Once a storm has been detected (that is, once the packet threshold set bel ow has been exceeded), the
Switch will shutdown the port to all incoming traffic with the exc eption of STP BPDU packets, for a time period
specified using the CountDown field. If the packet storm discontinues before the Countdown timer expires, the port will
again allow all incoming traffic. If this field times out an d the packet storm continues, the p ort will be placed in a
Shutdown Forever mode which will produce a warning message to be sent to the Trap Recei ver. Once in Shutdo wn
Forever mode, the only method of recovering this port is to manuall y recover it u sing the Port Configuration window
in the Configuration folder and selecting the disabled port and returning it to an Enabled status. To utilize this method
of Storm Control, choose the Shutdown option of the Action field in the window below.
To view this window click QoS > Traffic Control as shown below:
Figure 4 - 4 Traffic Control window