Ethernet switch is a network connection device, its main functions include physical addressing, network topology, error checking, frame sequence and flow control. The switch also has some new features, such as the rich Ethernet switch in addition to the basic functions, there are VLAN (virtual local area network) support for the link aggregation support, the use of more powerful.
Learning: The Ethernet switch understands the MAC address of the device connected to each port and maps the address to the corresponding port in the MAC address table in the switch cache.
Forwarding / Filtering: When the destination address of a data frame is mapped in the MAC address table, it is forwarded to the port of the destination node instead of all ports (if the data frame is broadcast / multicast to all ports) The
Elimination loop: When the switch includes a redundant loop, the Ethernet switch through the spanning tree protocol to avoid the generation of the loop, while allowing the existence of backup path.
In addition to being able to connect to the same type of network, the switch can also be interconnected between different types of networks, such as Ethernet and Fast Ethernet. Today, many switches are capable of providing high-speed connection ports that support fast Ethernet or FDDI, for connecting other switches in the network or providing additional bandwidth for critical servers with large bandwidth usage.
In general, each port of the switch is used to connect to a separate network segment, but sometimes in order to provide faster access speed, we can put some important network computer directly connected to the switch port. In this way, the key servers and important users of the network have faster access speeds and support greater traffic.
Finally, a brief summary of the basic functions of the switch:
1. Like a hub, the switch provides a large number of ports for cable connection, so you can use star topology cabling.
2. Like a repeater, hub, and bridge, when it forwards the frame, the switch regenerates an undistorted square electrical signal.
3. As with the bridge, the switch uses the same forwarding or filtering logic on each port.
4. As the bridge, the switch will be divided into multiple areas of the conflict domain, each conflict domain is a separate broadband, thus greatly improving the bandwidth of the LAN.
5. In addition to having the capabilities of bridges, hubs, and repeaters, the switch also provides more advanced features such as virtual local area network (VLAN) and higher performance.