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| 8 Port Hub |
Hub, Switch & Router Defined
Hub
A common connection point for devices in a network. Hubs are commonly used to connect segments of a LAN. A hub contains multiple ports. When a packet arrives at one port, it is copied to the other ports so that all segments of the LAN can see all packets.
Key Features of Hubs
Hubs classify as Layer 1 devices in the OSI model. At the physical layer, hubs can support little in the way of sophisticated networking. Hubs do not read any of the data passing through them and are not aware of their source or destination. Essentially, a hub simply receives incoming packets, possibly amplifies the electrical signal, and broadcasts these packets out to all devices on the network - including the one that originally sent the packet!
Technically speaking, three different types of hubs exist:
- passive
- active
- intelligent
Passive hubs do not amplify the electrical signal of incoming packets before broadcasting them out to the network. Active hubs, on the other hand, do perform this amplification, as does a different type of dedicated network device called a repeater. Some people use the terms concentrator when referring to a passive hub and multiport repeater when referring to an active hub.
Intelligent hubs add extra features to an active hub that are of particular importance to businesses. An intelligent hub typically is stackable (built in such a way that multiple units can be placed one on top of the other to conserve space). It also typically includes remote management capabilities via SNMP and virtual LAN (VLAN) support.
Switch
In networks, a device that filters and forwards packets between LAN segments. Switches operate at the data link layer (layer 2) and sometimes the network layer (layer 3) of the OSI Reference Model and therefore support any packet protocol. LANs that use switches to join segments are called switched LANs or, in the case of Ethernet networks, switched Ethernet LANs.
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| 24 Port Switch |
There are different types of network switch based upon the form and the configuration. On the basis of their form they are categorized into rack mounted, chassis or catalyst switch etc. And on the basis of configuration they are differentiated into managed, unmanaged, smart or enterprise managed switches.
Managed Switches:
A type of network switch in which different types of methods are used to manage the different parts of the network and can able to upgrade the working and the performance of the switch with the help of common methods of management is called as the managed network switch.
Unmanaged Network Switch:
Basically these networking switches are designed for those customers that are not able to spend more money because those are less expensive. A type of network switch in which interface is not involved is called as unmanaged network switches. They are designed for the direct use.
Smart Switches:
Basically the smart network switches are the important types of managed switches in which the specific management features are discussed. Typically these switches re used for the networking devices such as VLANs. They also increase the working ability of the parts connected by the switches
Advantages of Network Switch:
Due to the reliable and the easy working of the network switches to manage the network by joining the different segments of the network. Some of the particular advantages of the network switching are given below
- Network switches are very beneficial for the expenditure of the network and can also helpful in decreasing the load from the systems individually
- They are also helpful for the in maintaining and enhancing the performance of the network using switches
- In the networking data is transmitted in the form of the data packets and in these cases there are more chances of collision between the packets but network switches are also able to avoid the collision between the data grams
Router
A device that forwards data packets along networks. A router is connected to at least two networks, commonly two LANs or WANs or a LAN and its ISP.s network. Routers are located at gateways, the places where two or more networks connect. Routers use headers and forwarding tables to determine the best path for forwarding the packets, and they use protocols such as ICMP to communicate with each other and configure the best route between any two hosts.
Gateway
A gateway is either hardware or software that acts as a bridge between two networks so that data can be transferred between a number of computers. For example, when you send an e-mail to a friend or when you log in to a Web site, there is a gateway that allows the connection take place. Often, your connection to a Web site will involve many smaller connections to other servers along the way. In these cases, a number of gateways are used. In a completely unrelated story, Gateway is also the name of a popular direct-order PC manufacturer.
Bridge
Definition: A bridge device filters data traffic at a network boundary. Bridges reduce the amount of traffic on a LAN by dividing it into two segments.
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| Network Bridge |
Bridges operate at the data link layer (Layer 2) of the OSI model. Bridges inspect incoming traffic and decide whether to forward or discard it. An Ethernet bridge, for example, inspects each incoming Ethernet frame - including the source and destination MAC addresses, and sometimes the frame size - in making individual forwarding decisions.
Bridges serve a similar function as switches, that also operate at Layer 2. Traditional bridges, though, support one network boundary, whereas switches usually offer four or more hardware ports. Switches are sometimes called "multi-port bridges" for this reason.
Bridges serve a similar function as switches, that also operate at Layer 2. Traditional bridges, though, support one network boundary, whereas switches usually offer four or more hardware ports. Switches are sometimes called "multi-port bridges" for this reason.
What's the difference between a Hub, a Switch and a Router?
Hubs, switches, and routers are all devices that 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.
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.
"Varying degrees of magic happen inside the device, and therein lies the difference."
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.