Allied Telesis AT-FS705PD, Руководство по установке

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AT-FS705PD Fast Ethernet Switch Installation Guide
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The switch also checks the destination MAC address of each frame it receives.
The destination address is the MAC address of the end-node to which the
frame is intended. If the address is in the table, the switch directs the frame
directly to the port where the end-node is located. This helps to ensure that
end-nodes will only receive traffic that is intended for them and not have to
deal with traffic intended for other end-nodes.
If the destination address is not in the MAC address table, the switch
broadcasts the frame to all switch ports. When the destination end-node
responds, the switch will be able to match the address to a port so that the
next time a frame is destined to that particular end-node, the switch will be
able to forward the frame to the correct port instead of having to broadcast the
frame to all ports.
In some cases a switch will even discard a frame. If the switch receives a
frame that is destined to an end-node on the same port on which the frame
was received, the switch discards the frame.
The MAC address table in the AT-FS705PD switch can store up to 2,048 MAC
addresses. To prevent the table from becoming filled with addresses of end-
nodes that are no longer active, the switch has a MAC address aging timer.
This timer will delete a MAC address from the table if it does not see a frame
from the end-node with the address on any port after five minutes (300
seconds). The aging timer also helps to ensure that the table is correct should
an end-node be moved from one port on the switch to another port.
Store and Forward
The AT-FS705PD switch supports store and forward switching at Fast
Ethernet full-wire speed. Packets entering each port are stored in buffers.
Once the full packet is received, the switch will forward or discard the packet,
depending on its destination address and error status. This ensures that only
error-free packets destined for another segment will be transferred across the
switch, reducing network load. For example, if the packet entering from Port 1
is destined for an end-node on Port 2, the switch forwards the frame if the
frame does not contain any errors. If the packet from Port 1 is destined for an
end-node also connected to Port 1, the packet is discarded.