Planet Technology EV-401S Switch Operation, MAC Address Table and Learning, Store and Forward

4.SWITCH OPERATION

4.1MAC Address Table and Learning

The converter built in with a MAC address table that is composed of many entries. Each entry is used to store the address information of network nodes on the network, including MAC address, port ID, etc. The information is the most important base to do packet filtering and forwarding.

When one packet comes in from any port, the switch will learn the source address, port ID, and the other related information in address table. Therefore, the content of the MAC table will update dynamically.

4.2 Filtering and Forwarding

When one packet comes in from any port of the switch, it will check the destination address besides the source address learning. The switch will look up the address table for the destination address. If not found, this packet will be forwarded to all the other ports except the source port. If found and the destination address is located at different port from this packet comes in, the packet will be forwarded to the port where this destination address is located according to the information of address table. But, if the destination address is located at the same port as this packet comes in then this packet will be filtered.

4.3 Store and Forward

Store-and-forward is one kind of packet-forwarding methodology. As a store-and-forward switch, it will store the complete packet in the internal buffer and do the complete error checking before transmitting to the network. Therefore, no error packets will disturb the network. It is the best choice when a network needs efficiency and stability.

EV-401M / EV-401S User's Manual 19