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Ethernet Switches Tutorial

How is an Ethernet Switch used?
ports that auto-negotiate up to 1 Gigabit per Ethernet switches typically utilize RJ45 ports for
second access. The switch uses a MAC address UTP or STP connectivity to PCs, servers, routers
table to keep track of where PCs, etc. Many switches also feature high speed
What is an Ethernet Switch? servers or other connected devices are located. uplink ports where modules can be purchased to
An Ethernet switch is a multi-port network bridge Each device has a unique MAC (Media Access connect fiber optic or UTP cabling supporting
used to connect multiple PCs, servers, laptops or Control) address "burned" into the hardware. For speeds of 1 Gigabit per second or more. Cables
other Ethernet IP enabled devices such as example; if a PC on port one needs to "talk" to a are used to plug into the ports on the switch and
Networked Printers, NAS (Network Attached file server, the switch will look at its MAC address then into the Ethernet device (PC, router etc.) on
Storage), or IP cameras to a Local Area Network table and determine which port the file server is the other end.
(LAN). Most switches feature 10/100 Megabit per located on and send the PCs data to only that
second RJ45 ports although many newer switch port. This effectively relieves network congestion
designs now offer 10/100/1000 triple and is able to scale as your network grows.
speed
Managed and Unmanaged The diagram below shows a typical Ethernet Switch application
Unmanaged Ethernet switches, typically referred to as
"plug and play", are easy to install but do not provide
port level statics, management and control that is often WAN
required in larger networks where many switches are (Internet)
installed. Managed switches typically feature an SNMP
agent that allows port level control and statistics such
as collisions, packets in, packet out etc. Some managed
switches also feature filters where only certain devices,
PCs etc. are allowed to communicate on a certain port
of the switch. By using managed switches a network
administrator can see if a port may be malfunctioning
and sending bad packets onto the network and shut
that port off so the whole network does not go down.

Accessing CSMA/CD - Carrier sense multiple access with
Scheme: Collision Detection.
Speed: 10 Mbps/100 Mbps/1000 Mbps (1 Gbps).
Network In the diagram above you can see that Ethernet switches are used for sharing resources such as
Architecture: Bus, Star, Ring, Hybrid printers, networked file servers and router connections to the Internet or Wide Area Network (WAN).

Commercial Ethernet Switches Industrial Ethernet Switches
Commercial grade Ethernet switches are designed to be used in controlled There is a class of Ethernet Switches referred to as Industrial Ethernet
environments such as an IT closet or data center. Unlike Industrial switches which are designed to work in harsh environments where
Ethernet switches, commercial grade Ethernet switches typically have extreme temperatures, vibration, dust and moisture are present. These
more of a limited operating temperature range and often times have more Industrial rated switches generally have no moving parts such as fans
moving parts such as cooling fans which could be a single point of failure and utilize components that are designed for extreme temperatures etc.
(SPOF). Additionally, commercial grade switches will not stand up to shock In very moist environments or areas where condensation is present a
and vibration as an Industrial Ethernet switch would. Another concern is conformal coating is sometimes used to cover the entire PCB to protect
mean time between failure (MTBF). Some commercial grade switches the components. Typical installations for Industrial Ethernet switches
may have a lower MTBF than their industrial counterparts. Commercial include manufacturing facilities, mining, oil production, power plants,
grade switches typically cost less than industrial switches and are the waste water treatment plants and any other application where
perfect choice for controlled office/business environments. environmental extremes exist.

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