What is the Difference between "Switch", "Hub" and "Router"?

Question

Please give me guinine difference. Kindly give me serious answers only. Thank You all.

Answer 1

Switches and hubs are similar in that they provide client access to the local network. A router is a different device with a different purpose.

Computers create a network by connecting to each other. Today, we most commonly use Ethernet switches. These devices provide dedicated bandwidth to a device. Switches typically operate at 100MB to 1GB full duplex bandwidths. That is, the traffic and be sent and received at the same time. There are two different paths for traffic to traverse. This allows the device to communicate very efficiently on the network.

The switch knows the location of every device on the local network so it can route traffic directly to the port the the traffic is destined for.

Hubs were the forebearers to switches. Unlike the super efficiency of switching traffic, the hub sends all packets to all ports. Sort of like a yelling in a crowded room. Also unlike switches, hubs don't send traffic in full duplex. They have but one channel to each port. So, if both the hub and the device have something to send, it can collide on the wire and has to be resent. This used to be OK when there were few devices and they did not have much to say. Nowadays, this just does not cut it. Modern devices have a lot of chatter on the network and hubs just are too in effecient. There is no way to have a voice conversation or watch a video without constant interruptions.

Routers route. That is, they connect two different networks. Often times, they also connect two different network technologies, but they don't have to. For example, many homes have a little device that connects several wired or wireless computers. Thsi can be switched or a hub too. It also connects to the Cable service or DSL service (ISP). These little boxes have a router component the connects two different networks and network topologies. Since all the local computers can talk through the little box on the shelf, they live happily on the same broadcast domain. They can simply bark, or arp, out a request to find the name (MAC address) of their target. If their target is not on their local network (IP network) they need a way to find their target withouht having to learn every device in the universe. This is where the Router comes in! When a device determines the destination device is not local, they send the request to the router.

The router knows three important things. Who is connected to the networks they are directly connected to and who to send stuff to that is not directly connected. Traffic daisy chains like this across the globe. Each router just passes along traffic that is not locally connected until if reaches its destination.

So, a router is the traffic cop for traffic that is in a different network. Switches and hubs to the same basic thing, just diffrently. Switches offer superior performance and bandwidth to hubs. Hubs just plod along sending everything everywhere. Hubs are good for one thing these days. If you want to capture all the traffic on the local network, you need a hub to do this easily. Most switches cannot help you there.

Answer 2

A Router is actually a combination of the others, it has a built in switch, and acts as a hub, but it also has a DHCP server and NAT. A router can also contain a WAP or Wireless Access Point.

A hub allows for hooking up multiple computers, and may also have a switch in it. It does not have DHCP or NAT. It also will not have a WAP.

A switch is the most basic of these three networking components. It allows the transfer of data without reducing the available bandwidth divided by the number of devices on the netork.

If a hub that does not also contain a switch, is much slower than one which does have a switch.

Go to: http://www.howstuffworks.com

Click on Computer catagory, and you can locate explanations of what each of these is, how they work, and what they do for a network. It is very good reading.

Another difference between the three is the price. It is easy to see why a hub would cost more than a switch box, and a combo hub/switch more than a simple hub, and a router, especially with a WAP is more than all the others. Each has more technology and so has more capabilities and features. Another difference is a router has security options, which are not present in the hub or switch.

Answer 3

Hubs, switches, and routers are all devices which let you connect one or more computers to other computers, networked devices, or to other networks. Each has two or more connectors called ports into which you plug in the cables to make the connection. Varying degrees of magic happen inside the device, and therein lies the difference. I often see the terms misused so let's clarify what each one really means.

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A hub is typically the least expensive, least intelligent, and least complicated of the three. Its job is very simple: anything that comes in one port is sent out to the others. That's it. Every computer connected to the hub "sees" everything that every other computer on the hub sees. The hub itself is blissfully ignorant of the data being transmitted. For years, simple hubs have been quick and easy ways to connect computers in small networks.

A switch does essentially what a hub does but more efficiently. By paying attention to the traffic that comes across it, it can "learn" where particular addresses are. For example, if it sees traffic from machine A coming in on port 2, it now knows that machine A is connected to that port and that traffic to machine A needs to only be sent to that port and not any of the others. The net result of using a switch over a hub is that most of the network traffic only goes where it needs to rather than to every port. On busy networks this can make the network significantly faster.

A router is the smartest and most complicated of the bunch. Routers come in all shapes and sizes from the small four-port broadband routers that are very popular right now to the large industrial strength devices that drive the internet itself. A simple way to think of a router is as a computer that can be programmed to understand, possibly manipulate, and route the data its being asked to handle. For example, broadband routers include the ability to "hide" computers behind a type of firewall which involves slightly modifying the packets of network traffic as they traverse the device. All routers include some kind of user interface for configuring how the router will treat traffic. The really large routers include the equivalent of a full-blown programming language to describe how they should operate as well as the ability to communicate with other routers to describe or determine the best way to get network traffic from point A to point B.

A quick note on one other thing that you'll often see mentioned with these devices and that's network speed. Most devices now are capable of both 10mps (10 mega-bits, or million bits, per second) as well as 100mbs and will automatically detect the speed. If the device is labeled with only one speed then it will only be able to communicate with devices that also support that speed. 1000mbs or "gigabit" devices are starting to slowly become more common as well. Similarly many devices now also include 802.11b or 802.11g wireless transmitters that simply act like additional ports to the device.

Answer 4

a switch allows you to have different networking nodes on each port like a hub but the difference between the two is that a hub allows traffic to all of the ports. for example, if you wanted to ping a workstation the hub allows the ping traffic to go everywhere while a switch allows the ping traffic to just go to the workstation you pinged. a router allows you to have two different networks on it and it gets you out into the internet.