What is a network switch?
It is a small hardware device, which centralizes communications in one local area network (LAN) that has multiple devices connected.
Stand-alone Ethernet switch devices were popular on home networks years before home broadband routers became widely used. Routers used in modern homes integrate Ethernet switches directly into the unit as one of their primary functions.
High-speed switches are still popular in data centers and corporate networks.
Network switches are sometimes called MAC bridges, switching hubs or bridging hubs.
About network switches
While switching capabilities are available for various types of networks which include Token Ring, ATM, and Fiber Channel, Ethernet switches are the most popular type. Gigabit Ethernet speeds per individual link are supported by Ethernet switches such as those inside broadband routers; however, high-speed switches such as the ones in data centers often support 10 Gbps per link.
Different types of network switches support various numbers of devices that are connected. Consumer-grade switches offer either 4 or 8 connection for Ethernet devices, while 32 and 128 connections are usually supported by corporate switches, says Mitchell Morgan, technical engineer at Equustek Solutions Inc.
Switches can also be linked to each other; a daisy-chaining strategy makes it possible to add to a LAN progressively bigger number of devices.
Managed Vs. unmanaged hubs
Your selection of switch basically comes down to managed and unmanaged switches. Managed switches can be configured and adjusted remotely or locally and are more flexible compared to unmanaged switches in networking environments of companies. Unmanaged switches, on the other hand, need no configuration or installation and are popular in home networking environments, either built into other equipment, like routers, or as standalone devices. Also, managed switches offer higher network capacity, that is, packets can handle more units of data, simultaneously, compared to their unmanaged counterparts.
The unmanaged switch’s installation is simply connecting the incoming Cat. 5 or Cat. 6 Ethernet cable; the cable that connects the switch to the rest of your network, and connecting one or more new network devices, like extra computers, to the ports on the front of the network switch. Each port usually has a light which flashes on and off when an active device is plugged into it. Additionally, managed switches require the same manual installation but usually go hand in hand with configuration and management software, which you install on a server, or central computer, to permit the switch to be controlled from another location.
How a switch works
When a data packet is received by a network switch, it checks the source’s Media Access Control (MAC) address, which stores in an internal table referred to as a MAC table and the destination’s MAC address. If the network switch can locate the destination’s MAC address in its MAC table, it will transmit the packet to the port corresponding that address. If not, the network switch transmits the packet on all ports.
Network switches compared to routers and hubs
A network switch physically looks like a network hub. Contrary to hubs, however, switches can inspect incoming messages as they are received and have them directed to a specific communications port; a technology referred to as packet switching.
A network switch can determine each packet’s source and destination addresses and ensure the data is only forwarded to the specific devices, while in hubs; packets are transmitted to each port hubs apart from the one that received the traffic. It functions this way to preserve network bandwidth and typically enhance performance in comparison to hubs.
Network switches also look like routers. While switches and routers both centralize the connection of central devices, only network routers feature support for interfacing to outside networks, the internet or local networks.