Interlogix IFS MC250-4T Series, Руководство пользователя

Страница: 16 / 23

12 IFS MC250-4T/XXX Series User Manual
Switch Operation
Address Table
The Industrial Fast Ethernet Switch is implemented with an
address table. This address table is composed of many
entries. Each entry is used to store the address information of
a node in the network, including MAC address, Port No., and
etc. This information comes from the learning process of the
Industrial Fast Ethernet Switch.
Learning
When one packet comes from any port of Industrial Fast
Ethernet switch, the Industrial Fast Ethernet Switch will record
the source address, port no. and the other related information
in address table. This information will be used to decide either
forwarding or filtering for future packets.
Forwarding & Filtering
When one packet comes from a port of the Industrial Fast
Ethernet Switch, it will also check the destination address
besides the source address learning. The Industrial Fast
Ethernet Switch will lookup the address-table for the
destination address. If not found, this packet will be forwarded
to all the other ports except the port which this packet comes
in. And these ports will transmit this packet to the network it is
connected to. If found, and the destination address is located
at a different port that this packet comes in, the Industrial Fast
Ethernet Switch will forward this packet to the port where this
destination address is located according to the information
from address table. But, if the destination address is located at
the same port where this packet comes in, then this packet will
be filtered.
Store-and-Forward
Store-and-Forward is one type of packet-forwarding
techniques. A Store-and-Forward Industrial Switch stores the
incoming frames in an internal buffer and checks for any error