Network Topologies Mesh Topology provides each node in a network with a dedicated connection to every other node. Advantages: Improves reliability through redundancy and fault tolerance - the ability of the network to continue operation despite the presence of hardware or software faults. Mesh networks work well when the nodes are located at scattered points that do not lie near a common line. The Internet was deliberately designed using a mesh topology to allow sites to communicate during a nuclear war. Disadvantages: Expensive because of the large number of cables and connections required. Reconfiguration of the network or the addition of another node impacts all of the other nodes. Bus Topology - All nodes are connected to a central cable called the bus or backbone. A node wanting to communicate with another node sends a broadcast message onto the central cable, but only the intended recipient actually accepts and processes the message. Advantages: Less expensive because it requires less cable and hardware than other topologies because all of the nodes are in a line and lie near the bus. Bus networks are simple and reliable. Failure of one node does not affect others. Disadvantages: Entire network shuts down if there is a break in the main cable. Performance degrades as additional nodes are added. Heavy traffic slows down the network. Limited cable length and number of nodes. Problems can be difficult to isolate. Outdated coaxial network interface cards (NIC) are more difficult to find. Terminators are required at both ends of the backbone cable. There can be collisions when two nodes want to communicate at the same time on the same bus. Ring Topology - All devices are connected to one another in the shape of a closed loop or ring, so that each node is connected directly to two other nodes, one on either side of it. Advantages: Requires less wire than a star topology. All computers have equal access to the rest of the network. Even with many users, network performance is steady. Growth of the system has minimal impact on performance. Each node on the ring acts as a repeater, allowing ring networks to span greater distances than other physical topologies. Because data travels in one direction, high speeds of transmission of data are possible. When using a coaxial cable to create a ring network the service becomes much faster. Disadvantages: A failure in any cable or device breaks the loop and can take down the entire network. Response time is determined by the number of nodes on the ring - the more there are, the slower it works.
A bus is a communication system that connects multiple subsystems within a computer. An average computer system normally consists of several components such as a central processing unit, memory devices, and input/output (I/O) devices. The bus system consists of linking media like wires and connectors, and a bus protocol. Buses can be categorized as serial or parallel and synchronous or asynchronous. The bus lets the different components communicate with each other by allowing information to flow between units and devices.
“Network topology is the arrangement of the various network elements such as node, link, of computer network. Basically, it is topological structure of a network which ether be physically or logically.”
The attacks targets the routing information which is being exchanged among nodes. The data in the table is altered and attacker then attracts or repel network traffic, generate false error messages, increase latency or even partition the network. The next node generally depends on the previous node(s) table to create routing paths.
Wireless networks – While the term wireless network may technically be used to refer to any type of network that is wireless, the term is most commonly used to refer to a telecommunications network whose interconnection between nodes is implemented without the use of wires, such as a computer network. Wireless telecommunication networks are generally implemented with some type of remote information transmission system that uses electromagnetic waves, such as radio waves, for the carrier and this implementation usually takes place at the physical level or “layer” network.
Although the large data transfers monopolized the services on the local network, the main network components still functioned properly. The impact of the knowledge management system They began to duplicate each other’s functionality. The messages began repeating each other in an endless loop until the network totally disabled.
To attempt to define a network in a few sentences would be a fool’s errand. A network could be seen as simply a grid of interconnecting connections between multiple bodies. However when this vision is applied to real-world systems, they all start to differ. There is not anything that exists in the universe that is not part of a network. A network is the result of different parts or members which have similarities in parts of their identity. This similarity that they have in common, they will also have with other bodies forming a network between them. Most of these factors of identity are different from those of most others. As a result, each factor will be in common with different other members of different networks. Each factor includes this body in a multitude of networks. This means that no one thing is in one and only one network, but is included in many.
The internet was created to test new networking technologies developed to eventually aid the military. The Arpanet, advanced research projects agency network, became operational in 1968 after it was conceived by Leanard Roberts (Watrall, T101, 2/2). Ever since the Arpanet began in 1968, it grew exponentially in the number of connected users. Traffic and host population became too big for the network to maintain, due to the killer application known as email created in 1972. The outcry for a better way sparked the development of the NSFNet. The National Science Foundation Network replaced Arpanet, and ultimately had many positive effects. This early division of the internet spread its netw...
Spanning tree protocol is a protocol that prevents loops that are not wanted in a network. In order for a network to work properly it has to have only one active path between two network stations. If there are multiple active paths between stations loops can and will occur. When loops occur, there can sometimes be duplicate messages in the network. The loops are created by the network and if the devices that connect the network segments are all configured to forward, they will continuously forward frames into an endless network loop. If there are enough loops going then a frame will not reach its destination. The reason duplicate messages occur is because sometimes switches will see situations appear on both sides of it. When this occurs that is when spanning tree protocol comes in. In order to shut down the loops bridges and switches exchange BPDU messages with other bridges and switches to detect loops and then remove them by shutting down selected bridge interfaces. BPDU is short for bridge protocol data unit. Bridge protocol data units are part of the spanning tree protocol and they help describe and identify the parts of a switch port. The bridge protocol data unit allows switches to obtain information about each other. All the switches gather information from each other by exchanging data messages. In order for them to exchange messages they have to elect a root switch for the topology. The root switch has to be unique. The way they elect they have to have a unique switch for every local area network segment. To exchange messages they have to remove all loops by putting them in a backup state. Now to talk about states there is 5 different states. Two of the five states do not participate in frame forwarding. Frame forwarding is what the three main states do. The three main states are listening, learning, and forwarding. The other 2 are blocking state and disabled state. When you enable the spanning tree protocol the network goes through the blocking state and then the listening state and learning state are enabled after being turned on. If the protocol is properly configured the ports are stabilized to the forwarding or blocking state. The blocking state does not participate in the frame forwarding. It removes frames that are received from the attached segment. It also discards frames from another port for forwarding.
Perhaps the most redundant, fault-tolerant of all network topologies is the mesh LAN. Each node is connected to every other node for a true point-to-point connection between every device on the network.
The history of the internet shows that the internet is not a new medium. The internet was initially created in the 1960's to as a way for the United States to stay connected in case of a nuclear fallout due to the possible consequences of the Cold War. F...
b) Information cannot be shared at a wider range to different receivers at distanced locations
Networks in organisation are dynamic and complex entities which can be quite challenging to configure and manage. (Kim & Feamster 2013). These corporate networks consist of multiple routers, switches, firewalls, middleboxes and a particular advantage of network management is the ability to monitor the entire business network. As all the devices are interconnected with many event occurring simultaneously, problems with once device can eventually lead and spread throughout...
On October 29, 1969 Lawrence Roberts had created the first two nodes to travel between UCLA and SRI International. This project was originally conducted under the Advanced Research Projects Agency to counteract the USSR’s launch of the Sputnik. After the creation it had been called the Arpanet, and would be used specifically for government networks until the early 90’s. In 1990 the World Wide Web had been created as an online public network for everyday civilians to use. At least three decades later the web has grown to include over a million sites, while maintaining the original governments use to maintain a network between locations.
With the design separated into smaller logical pieces, network design problems can be easier to solve through divide and conquer techniques. Vendors who follow the model will produce equipment that is much more likely to be compatible with equipment from other vendors. The OSI model also provides for more extensible network designs. New protocols and other network services are easier to add to a layered architecture.
So who was the genius behind the information superhighway, you ask? Well let’s take a step back to the sixties, a decade when Cold War tension caused nationwide fear of nuclear warfare. Early in the decade, two groups of researchers, privately owned RAND Corporation (America’s leading nuclear war think-tank) and federal agency ARPA (Advanced Research Projects Agency), grappled with a bizarre strategic mystery: in the event of nuclear war, how could political and military officials communicate successfully? It was obvious that a network, linking cities and military bases, would be necessary. But the advent of the atomic bomb made switches, wiring, and command posts for this network highly vulnerable. A “nuclear-safe” network would need to operate with missing links and without central authority.