NETWORKING
Explain Hub
OR
Explain Hub with Types:-
->A Hub is a networking device which receives signal from the source, amplifies it and send it to multiple destinations or computers. If you ever some across subject 'Computer Networking' then you must heard this word. Sometimes, hubs are also called Ethernet Hub, Repeater Hub, Active Hub and Network Hub. Basically it is a networking device which is used multiple devices like Computers, Servers etc. to each other and make them work as a single network segment. Hubs are used in 'Physical Layer' of OSI Model.
->Practically Hubs is a small box in rectangular shape which have multiple ports for connecting various devices to it. It receives its power supply from auxiliary power sources. The main work of Hub is to receive incoming data signals, amplify them in the form of electrical signals and then send them to each connected device. A Hub may contain a number of ports. Minimum amount of ports that a hub can have is 4 and it can have up to 24 ports for connecting various devices and peripherals to it.
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->Types of Hub :On the basis of its working methods, the Hubs can be divided into three types, given as:
1) Passive hub 2) Active hub 3) Intelligent hub
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1. Active Hub: As its name suggests, Active Hub is a hub which can amplify or regenerate the information signal. This type of bus has an advantage as it also amplifies the incoming signal as well as forward it to multiple devices. This Bus is also known as Multiport Repeater. It can upgrade the properties if incoming signal before sending them to destination.
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2. Passive Hub: Passive Hub works like a simple Bridge. It is used for just creating a connection between various devices. It does not have the ability to amplify or regenerate any incoming signal. It receives signal and then forward it to multiple devices.
Explain Network Interfaces card (NIC):
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->Short for Network Interface Card, the NIC is also referred to as an Ethernet card and network adapter. It is an expansion card that enables a computer to connect to a network; such as a home network, or the Internet using an Ethernet cable with an RJ-45 connector.
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->Some NIC (Network Interface Card) cards are meant for wired networks while others are for wireless network. Most widely used wired LAN Technology is Ethernet. Ethernet based NIC (Network Interface Card) cards are available in every local electronic hardware shops. Normal speed rating of Ethernet based wired NIC (Network Interface Card) available these days are 10/100/1000 Mbps (Megabits per second).
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->Every computer participating in network must have at least one NIC. Computers can have more than one NIC card also NIC (network interface cards) also provide a buffer for incoming and outgoing data, so that the computer can compensate for latency issues. Many modern devices have network interface cards built into them, as standards have made Ethernet and IEEE 802.11.
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->Every NIC (Network Interface Card) has a 48-bit globally unique identifier called as MAC Address (Media Access Control Address) burned into its ROM chip. This MAC address is used to deliver Ethernet Frames (packets) to a computer.
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->The NIC driver software passes the data between the Operating System and the NIC. Latest Operating Systems include different NIC driver software for almost all major NIC vendors. One NIC can handle a number of Ethernet connections by attaching a switch or router to it. While most people are used to standalone routers, many enterprise and server-grade routers are full servers attached to switches. In some cases, two or more NICs might be used to provide more through-put.
