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These are very fast computers with a large amount of RAM and storage space, along with a one or more fast network interface card s. The network operating system provides tools to share server resources and information with network users.
A sophisticated permissions-handling system is included, so that access to sensitive information can be carefully tailored to the needs of the users. For small networks, a singe network server may provide access control, file sharing, printer sharing, email, database, and other services.
The network server may be responding to requests from many network users simultaneously. For example, it may be asked to load a word processor program to one workstation, receive a database file from another workstation, and store an e-mail message during the same time period.
This requires a computer that can store and quickly share large amounts of information. When configuring such a server, budget is usually the controlling factor. The following guidelines should be followed: Fastest Switches and routers s multiple large, fast hard drives Extra expansion slots Fast network interface card s Optionally if no other such devices are available on the network: A typical workstation is a computer that is configured with a network interface card, networking software, and the appropriate cables.
Workstations do not necessarily need large storage hard drives, because files can be saved on the file server. Almost any computer can serve as a network workstation.
These devices typically have modest internal storage, but enough power to serve as a workstation for users on the go. These machines nearly always have a wireless adapter to allow quick network connections without cumbersome cabling.
In a school environment with good wireless coverage, a mobile device user can move about the campus freely, and remain continuously connected to the network.
Network Interface Cards The network interface card NIC provides the physical connection between the network and the computer workstation. Most NICs are internal, and they are included in the purchase of most computers.
Network interface cards are a major factor in determining the speed and performance of a network. It is a good idea to use the fastest network card available for the type of workstation you are using.
The most common network interface connections are Ethernet cards and wireless adapters. Ethernet Cards Ethernet cards are usually included with a computer, although additional ethernet cards can be purchased and installed on most computers.
Ethernet cards can contain connections for either coaxial or twisted pair cables or both See fig. If it is designed for coaxial cable, the connection will be BNC. If it is designed for twisted pair, it will have a RJ connection. Some Ethernet cards also contain an AUI connector. This can be used to attach coaxial, twisted pair, or fiber optics cable to an Ethernet card.
When this method is used there is always an external transceiver attached to the workstation. Only the RJ connector is found on most modern ethernet cards See the Cabling section for more information on connectors. External wireless adapters can be purchased and installed on most computers having an open USB Universal Serial Bus port, or unused expansion slot.
See the Cabling section for more information on connectors. Switches An ethernet switch is a device that provides a central connection point for cables from workstations, servers, and peripherals. Most switches are active, that is they electrically amplify the signal as it moves from one device to another.
The predecessor of the switch was the hub, which broadcasted all inbound packets out all ports of the device, creating huge amounts of unnecessary network traffic.
Modern switches build a port map of all IP address which respond on each port, and only broadcasts on all ports when it doesn't have a packet's target IP address already in its port map. Usually configured with 8, 12, or 24 RJ ports Often used in a star or tree topology Available as "managed" or "unmanaged", with the later less expensive, but adequate for smaller networks direct replacements for hubs, immediately reducing network traffic in most networks Usually installed in a standardized metal rack that also may store network serversbridgesor routers Repeaters Since a signal loses strength as it passes along a cable, it is often necessary to boost the signal with a device called a repeater.
The repeater electrically amplifies the signal it receives and rebroadcasts it. Repeaters can be separate devices or they can be incorporated into a concentrator. They are used when the total length of your network cable exceeds the standards set for the type of cable being used.
A good example of the use of repeaters would be in a local area network using a star topology with unshielded twisted-pair cabling. The length limit for unshielded twisted-pair cable is meters.
The most common configuration is for each workstation to be connected by twisted-pair cable to a multi-port active concentrator. The concentrator amplifies all the signals that pass through it allowing for the total length of cable on the network to exceed the meter limit.
Bridges A bridge is a device that allows you to segment a large network into two smaller, more efficient networks.UniFi is quickly expanding to a full Software-Defined Networking (SDN) solution with seamless integration of high-performance switching, gateways, and more.
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using local accounts created on each device, you need to read this article. Being relatively new to the Cisco IOS myself, I get excited when I find a time saver such as this. Radia Perlmans Interconnections is recognized as a leading text on networking theory and practice.
It provides authoritative and comprehensive information on general networking concepts, routing algorithms and protocols, addressing, and the mechanics of bridges, routers, switches, and hubs.
Recommended Hub Model. D-Link DETP 10Mbps Ethernet Mini Hub 5-Port D-Link DETP 10Mbps Ethernet Mini Hub 5-Port Buy Now At Amazon. Since hubs have pretty much been superseded by switches, “plain” hubs are few and far between these days. Routers for home networks (often called broadband routers) are designed specifically to join the home network to the Internet for the purpose of Internet connection sharing.
In contrast, switches (and hubs) are not capable of joining multiple networks or sharing an Internet connection.
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