Network Switch Basics
In today’s increasingly mobile world, there has been a massive push for the propagation of wireless networking. Everyone seems to love being connected as they move about their day.
With the prevalence of wireless accessibility, people do not stop to think about what happens in the background to enable that connectivity. There is an infrastructure that must be set up, tested and maintained to allow it to remain viable and useful. Much of the time, this process can become very costly with regards to labor, equipment expense and troubleshooting. Reliability is another key factor that must also be considered. One of the solutions to create a stable network, instead of using wireless, is through the use of structured cabling and network Ethernet switches.
A network switch is a tool responsible for the connections between the systems and equipment that you wish to interact with and to share data amongst. These connections are generally created through the use of structured cabling that links both the station side (the side you interact with) and the device that you are trying to share data with, such as a server or another computer.
A network switch can be thought of as a middleman that directs traffic to its correct place. In short, if a device tries to retrieve data from another source, the switch will check to see if it knows where the destination is. If it does not know where the destination is, it will send the packets off to another device like a router and let that device determine what to do with the information. Depending on the type, layer 2 or layer 3, a switch will reside respectively on the Data Link layer or the Network layer of the OSI model.
Layer 2 switches are some of the most common, as they tend to be less expensive and perform well. They use a device’s physical address (MAC address) from incoming message frames to determine which output port to forward the information out of. A switch is able to do this by keeping a MAC address table from ARP requests for comparing incoming frame information.
Layer 3 switches possess the same capability and behave in much the same way as a layer 2 switch; however, they also possess the ability to route between different subnets or VLANs that may exist on a local area network. This can take quite a load off of a router, leaving it to solely handle network access that is off of the LAN.
Switches allow information to be passed along in a much more discrete and efficient way compared to network hubs. Switches enable multiple users to access network resources by creating specific pathways for information to flow between the connections without any interactions from other data packets that could potentially be on the same network segment. They effectively reduce the amount of collisions that may occur between data packets, since the switch knows where it needs to send information based on its MAC table. This is very different from a hub. A hub broadcasts data to each connected device until the correct destination is reached, which can result in data collisions as well as security issues.
How does this translate into the home and consumer side of things? An inexpensive switch can allow a person looking to create a home network to connect all of their devices together without the fear of slow data sharing caused by packet collisions, all while using the same Internet connection. They also allow for the centralization of connections within the home, making management much easier. The first step in choosing the correct switch for your home is deciding on what type you may want. Luckily, there are a few options.
One thing it also fails to mention are home Wi-Fi routers. They are all in one devices that almost have four extra LAN ports for connecting a LAN cable. These ports are made possible as they have an integrated "switch" device. If that is sufficient then a consumer might not need a switch.
In some larger homes, you might want to add a switch connected to a Wi-Fi router to increase the number of available of ports. First reason, a homeowner might need LAN ports immediately in wall outlets. Second, for installing and filling the home with Wi-Fi access points. Third reason is for other IP devices such as security cameras, IP phones, and others. So, one major feature excluded in the article is PoE. An advanced home network might need to deploy a PoE switch if it has security cameras and Wi-Fi access points at the same time to avoid the need of using power adapters for each networking device. PoE discussion can be expanded as it has two power level standards which can be an issue with Wi-Fi ac standard access points.
Wanted a USB to RJ45 dongle for the WiiU instead of using it's wireless. EB games/Dick Smith didn't sell Nintendo's dongle anymore so got near enough what i thought might work. One of those USB to RJ45 but came with two ends, i thought one end was just another spare LOL. Was a USB to USB extension over Cat5 cable and had the RJ45 straight into the switch, matter of minutes it was a lesson learned...
Not proud of it, but was funny.
You are pretty critical of a "Switch 101" summary on a web site. You want to read about home wifi routers and PoE in a "Switch 101" article that does a good job of bringing the definition of the basic functionality of a switch to people. Maybe you're looking for the wrong information in an article that clearly isn't called "here's how you connect and configure your entire home network 101".
This article sticks to the subject of switches and brings it down to a pretty understandable level for most people. It really is well organized and summarizes things at a general level.
I would think PoE and the like could be addressed in a 102 article that describes what else a switch is capable of and also get into topics on managed switches and their value.
Back to duplex, assuming an ethernet connection, half duplex vs full duplex will NEVER cause a collision because transmit and receive are on seperate wires. The real difference between half and full duplex are bandwith. Full duplex is effectively double the bandwith of a half duplex connection. 100mbps half, can send, or receive at 100mbps max. Full duplex can send AND receive at 100mbps in each direction at the same time without any delays, so effectively you have 200mbps of bandwith. What is useful about this is for troubleshooting purposes, if you have a slow network connection, one of the first things to check is the negotiated speed. If you have a gigabit network, you should see 1gbps as your connection speed(1gbps is always full duplex, 1gbps half duplex doesn't exist in ethernet specs) if you see 100/half, you know something is wrong. Either a bad cable, driver, or some other issue is preventing your connection from negotiating properly at the maximum supported speed.
You don't even need a DHCP server running to connect devices to the internet through a router.