Hardware and Networking - What is Networking Hardware?
Hardware and Networking includes all computers, peripherals, interface cards and other equipment needed to perform data-processing and communications within the network.
Hardware and Networking - File/Network Servers.
One or more network servers is a part of nearly every local area network. 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. 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.
multiple large, fast hard drives
Fast network interface card(s)
Optionally (if no other such devices are available on the network):
Hardware and Networking - Workstations.
A typical workstation is a computer that is configured with a network interface card, Hardware and 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.
Hardware and Networking - Network Adapters.
There are many different names for Hardware and Networking adapters, including network cards, Network Interface Cards, NICs. A network card’s job is to physically attach a computer to a network, so that the computer can participate in network communications.
The first thing that you need to know about network cards is that the network card has to match the network medium. The network medium refers to the type of cabling that is being used on the Hardware and Networking. At one time making sure that a network card matched the network medium was a really big deal, because there were a large number of competing standards in existence. For example, before you built a network and started buying network cards and cabling, you had to decide if you were going to use Ethernet, coaxal Ethernet, Token Ring, Arcnet, or one of the other Hardware and Networking standards of the time. Pretty much the only type of wired network used by small and medium sized businesses is Ethernet. You can see an example of an Ethernet network card.
Modern Ethernet networks use twisted pair cabling containing eight wires. Phone cords use RJ-11 connectors as opposed to the RJ-45 connectors used by Ethernet cable. You can see an example of an Ethernet cable with an RJ-45 connector, shown in Figure B.
Hardware and Networking - Network Interface Cards.
The network interface card (NIC) provides the physical connection between the network and the computer workstation. 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.
Hardware and Networking - 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. 1). If it is designed for coaxial cable, the connection will be BNC. Ethernet card.
RJ-45, AUI, and BNC connectors
Hardware and Networking - Wireless Adapters.
Wireless adapters are found in most portable devices, such as laptops, smart phones, and tablet devices. (See the Cabling section for more information on connectors.)
Hardware and Networking - Switches.
An Ethernet switch is a device that provides a central connection point for cables from workstations, servers, and peripherals. 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-45 ports
direct replacements for hubs, immediately reducing network traffic in most networks
Usually installed in a standardized metal rack that also may store network servers, bridges, or routers
As you can see, computers use network cards to send and receive data. The data is transmitted over Ethernet cables. However, you normally can’t just run an Ethernet cable between two PCs and call it a network.
Broadband is a type of network in which data is sent and received across the same wire. In contrast, Ethernet uses Baseband communications. Base band uses separate wires for sending and receiving data. What this means is that if one PC is sending data across a particular wire within the Ethernet cable, then the PC that is receiving the data needs to have the wire redirected to its receiving port.
You can actually network two PCs together in this way. The problem with using a cross over cable to build a network is that the network will be limited to using no more and no less than two PCs. Rather than using a cross over cable, most networks use normal Ethernet cables that do not have the sending and receiving wires reversed at one end.
Each computer on a Hardware and Networking would be connected to a hub via an Ethernet cable.
A hub is a device that acts as a central connection point for computers on a network
A hub has two different jobs. Every computer plugs into the hub (multiple hubs can be daisy chained together if necessary in order to accommodate more computers).
The hub’s other job is to arrange the ports in such a way so that if a PC transmits data, the data is sent over the other computer’s receive wires.
The secret lies in the network card. When a computer on an Ethernet network transmits data across an Ethernet network containing PCs connected to a hub, the data is actually sent to every computer on the Hardware and Networking. As each computer receives the data, it compares the destination address to its own MAC address. As you can see, when computers are connected via a hub, every packet gets sent to every computer on the Hardware and Networking. As the number of PCs on a collision domain increases, so does the number of collisions. As the number of collisions increase, Hardware and Networking efficiency is decreased. This is why switches have almost completely replaced hubs.
A switch looks a lot like a hub, but performs very differently
Switches greatly improve a network’s efficiency. For example, just because computer A is communicating with computer B, there is no reason why computer C can’t simultaneously communicate with computer D.
Hardware and Networking - Repeaters.
The length limit for unshielded twisted-pair cable is 100 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 Hardware and Networking to exceed the 100 meter limit.
Hardware and Networking - Bridges.
A bridge is a device that allows you to segment a large Hardware and Networking into two smaller, more efficient networks. A bridge monitors the information traffic on both sides of the Hardware and Networking so that it can pass packets of information to the correct location. Most bridges can "listen" to the Hardware and Networking and automatically figure out the address of each computer on both sides of the bridge. The bridge manages the traffic to maintain optimum performance on both sides of the network. It keeps information flowing on both sides of the network, but it does not allow unnecessary traffic through. Bridges can be used to connect different types of cabling, or physical topologies.
Hardware and Networking - Routers.
Routers are the traffic directors of the global internet. Routers communicate with each other, and forward network packets out of or into a Hardware and Networking. The browser ships the request for that IP address off to the network card, which bundles the request into an Ethernet packet, destined for 74.125.67.103. The network card sends the packet to the gateway of your network, which opens the header of the packet, and makes a determination that the packet is traveling out of your Hardware and Networking, in search of 74.125.67.103. Your network's router has routing tables which it has been building from communicating with other routers, and potentially augmented with "static routes", which are specific paths added by your network's administrators to make the task of accessing certain networks easier, or faster, or in some cases, not possible. The packet finally reaches the router of the network at 74.125.67.103, which dutifully delivers the packet to the server at that IP address. While bridges know the addresses of all computers on each side of the network, routers know the addresses other routers which in turn know about their own networks. Routers can even "listen" to entire networks to determine which sections are busiest -- they can then redirect data around those sections until traffic congestion clears.
So, routers are Hardware and Networking gateways. They move network packets from one network to another, and many can convert from one network protocol to another as necessary.
Hardware and Networking - Firewalls.
A firewall is a networking device that is installed at the entrance to a LAN when connecting a networks together, particularly when connecting a private network to a public network, such as the internet. The firewall uses rules to filter traffic into and out of the private network, to protect the private network users and data from malevolent hackers.
Firewalls are either Hardware and Networking or software, depending on their intended use. A firewall used to protect a network is a Hardware and Networking device that should be installed in the network between the router and the network. The public network is connected to the untrusted network port, and the private network is connected to the trusted port.
Firewall rules are usually simple, consisting of a verb, either allow or deny, the direction of the traffic, either inbound or outbound, and an address or other network traffic identifier.
Allow outbound all (all private network users can do anything on the public network)
Allow inbound port 80 (allow internet web traffic to come into network to find web servers)
Allow inbound port 80 destined to 170.200.201.25 (allow inbound web traffic to a specific web server on your private network)
Deny inbound from 201.202.1.1/24 (deny all inbound traffic from a specific IP address or range of addresses)
Software firewalls are commonly included in modern hardware and networking workstation and server operating systems.
