User`s guide

DGS-3204 Ethernet Switch Management User’s Guide
DGS-3204 Management 23
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Flow Control State
Enables or disables IEEE 802.3x flow
control on the port. Flow control allows the port to send a Pause packet to
a transmitting IEEE 802.3x-compliant device, so that it’s buffers don’t
overflow and data is not lost.
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Lock State
When locked, automatic learning for all stations
connected to this port will stop and entries in the Forwarding Table for
all devices residing on this port will age out. The only traffic this port
will allow is traffic from machines whose MAC address is manually
entered in the Static Forwarding Table.
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Priority
Sets the priority for traffic arriving at this port to high,
normal or low. Higher priority packets are processed first in the switch’s
packet queue.
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STP State
Enables or disables Spanning Tree on this port. Spanning
Tree allows backup connections and prevents signal loops on the
network.
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HOL State
Enables or disables Head-Of-Line Blocking Prevention
on this port. Head-of Line blocking occurs when a packet originating on
Port 1, for instance, needs to be forwarded to Ports 2 and 3. If Port 2 is
occupied (causing the packet to be held in memory until the port is free),
the packet destined for Port 3 will also be delayed. Cumulatively, these
delays can have a noticeable effect on overall network performance.
Enabling the HOL State prevents Head-of-Line blocking from occurring.
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Broadcast Storm Rising Action
This setting will be
activated when the switch detects that 80% of packets on the segment
connected to the port are broadcast packets and the port surpasses 30%
utilization. When these criteria are met, the port can be configured to Do
Nothing, Block or Block and Trap. The Do Nothing setting causes the
switch to operate normally, in other words, ignore the broadcast storm
condition. The Block setting causes the port to drop all broadcast frames,
thus isolating the broadcast storm. Block and Trap performs the same
action as Block, except it also sends a trap to the designated Trap
Recipient informing them of the situation.
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Broadcast Storm Falling Action
This setting will be
activated when a Broadcast Storm Rising Action has occurred and the
switch detects that port utilization has dropped below 10%. This setting