IFS MC251-4P/1S and NS2051-4P/1T User Manual 15
each node in the network, including MAC address, Port No.,
etc. This information comes from the learning process of the
Industrial Fast Ethernet Switch.
Learning
When one packet comes from any port of the Industrial Fast
Ethernet switch, the Industrial Fast Ethernet Switch will record
the source address, port no. and other related information in
the address table. This information will be used to decide
either forwarding or filtering for future packets.
Forwarding & Filtering
When one packet comes from another 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 came in.
And these ports will transmit this packet to the network it's
connected to. If found, and the destination address is located
at a different port from 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 with 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 errors
from the frames before transmission. Lack of error packet
occurrence is important for an efficient and stable network..
