Appendix C Switch Operation; Address Table; Learning; Forwarding & Filtering - Planet SOHOConnect Series Manual

Appendix C Switch Operation

Address Table

The Switch is implemented with an address table. This
address table composed of many entries. Each entry is used
to store the address information of some node in network,
including MAC address, port no, etc. The information comes
from the learning process of Ethernet Switch.

Learning

When one packet comes in from any port. The Ethernet
Switch will record the source address, port no. and the other
related information in address table. These information will be
used to decide either forwarding or filtering for future packets.
Forwarding & Filtering
When one packet comes from some port of the Ethernet
Switch, it will also check the destination address besides the
source address learning. The 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 connected. If found, and the
destination address is located at different port from this
packet comes in, the 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,
when this packet will be filtered. Thereby increasing the
network throughput and availability
22