What device is used to connect computers in a star topology network?

Domain 4: Communication and Network Security (Designing and Protecting Network Security)

Eric Conrad, ... Joshua Feldman, in CISSP Study Guide (Third Edition), 2016

Star

Star topology has become the dominant physical topology for LANs. The star was first popularized by ARCNET, and later adopted by Ethernet. Each node is connected directly to a central device such as a hub or a switch, as shown in Figure 5.17.

Figure 5.17. Star Topology

Exam Warning

Remember that physical and logical topologies are related, but different. A logical ring can run via a physical ring, but there are exceptions. FDDI uses both a logical and physical ring, but Token Ring is a logical ring topology that runs on a physical star, for example. If you see the word “ring” on the exam, check the context to see if it is referring to physical ring, logical ring, or both.

Stars feature better fault tolerance: any single local cable cut or NIC failure affects one node only. Since each node is wired back to a central point, more cable is required as opposed to bus (where one cable run connects nodes to each other). This cost disadvantage is usually outweighed by the fault tolerance advantages.

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1.Which device is used for connecting the computers in a star topology? A. Router B. Bridge C. Hub.. 1 answer below »

1.Which device is used for connecting the computers in a star topology?

A. Router B. Bridge C. Hub D. Repeater

2. Which topology is the combination of multiple topologies?

A. Star topology B. Bus topology C. Hybrid topology D. Mesh topology

3. In which topology data is transferred in a circular pattern?

A. Star topology B. Ring topology C. Bus topology D. Hybrid topology

4. Which of the following topologies is the most complex but effi cient?

A. Star topology B. Bus topology C. Ring topology D. Hybrid topology

5. What is the technique used for routing the packets to the destination according to their addresses?

A. Circuit switching B. Packet switching C. Routing D. None of the above

6. Which one of the following is not a network protocol?

A. FTP B. HTTP C. SMTP D. NMP

7. A set of rules that are used for communication between two networks is referred to as:

A. Network software B. Network media

C. Network protocol D. Network operating system

8. Explain the process of data communication with the help of a diagram.

Mar 29 2021 09:09 AM

star network

A star network is a local area network (LAN) topology in which all nodes -- personal computers (PCs), workstations or other devices -- are directly connected to a common central computer that is often referred to as a hub.

Andrew Froehlich, West Gate Networks

10 Aug 2021

What is a star network?

A star network is a local area network (LAN) topology in which all nodes -- personal computers (PCs), workstations or other devices -- are directly connected to a common central computer that is often referred to as a hub. Therefore, a star network is often referred to as a hub-and-spoke network topology.

Every workstation connected to the hub is indirectly connected to each workstation using the hub as an intermediary device. Star networks are typically deployed at the access layer of enterprise networks. The access layer uses a centralized network switch to connect all endpoints to the rest of the LAN.

This graphic shows a star network consisting of a central hub. Each workstation is shown as a PC or laptop with the central hub interconnecting all devices. The lines that interconnect endpoint PCs and laptops are the spokes of the star topology. In the real world, a star network can consist of either wired or wireless connections. In this specific case, each spoke is connected to a hub by a wired connection.

How does a star network work?

Because a star network uses a centralized hub, that hub is responsible for controlling communications between devices. However, there are different ways that a central hub can manage these communications. For example, an Ethernet hub is a network device that simply listens to a communication destined for a device on a different spoke and then retransmits -- or broadcasts -- the message out to all spokes. This is the simplest form of a network hub, as it only must repeat the message to all other connected spokes. But this method can become inefficient quickly, as each communication is sent out to all spokes, as opposed to only the spoke the message was intended for.

If too many devices begin communicating on a network hub, the amount of broadcast traffic can quickly reduce network throughput. It also places the Ethernet hub where it physically looks like a star network topology but operates like a traditional bus network topology.

An Ethernet switch, on the other hand, may look like an Ethernet hub from a physical cabling perspective, but it is far more sophisticated when it comes to how the centralized device handles the transmission of communications to the intended spoke device. Ethernet switches eliminate the need to broadcast communications out to all spokes on the star network. Instead, the Ethernet switch maintains a media access control (MAC) address table. This table statically or dynamically maps the physical MAC address to the port or spoke where the spoke endpoint resides. Therefore, if an Ethernet switch knows the MAC address and specific spoke that the MAC address lives on, it can use this information to send a communication directly out to a single spoke, as opposed to broadcasting the communication to all spokes -- unnecessarily using network bandwidth. Ultimately, an Ethernet switch accomplishes the same goal as an Ethernet hub with the added benefit of better network transport efficiency.

Comparing star network topologies with other topologies

The star network topology works well when workstations are deployed randomly throughout a building or facility. With the hub-and-spoke design, it is easy to add or remove workstations, as all cabling is pulled and connected to a central hub.

From a cabling perspective, if the workstations are reasonably close to the vertices of a convex polygon and the system requirements are modest, the ring network topology may serve the intended purpose at a lower cost than the star network topology. If the workstations lie nearly along a straight line, the bus network topology may be best.

In a star network, a cable failure on a single spoke will only affect the spoke endpoint that it links to the central computer. All the other workstations will continue to function normally with the exception that they will not be able to communicate with the device that resides on the failed spoke. In other words, a star network is powerful from this perspective, as a failure on one spoke does not affect communications of other spokes that are in a functioning state. However, the caveat is that, if the central hub were to fail, all spokes on the star network also fail. If any workstation goes down, none of the other workstations will be affected. Therefore, if network redundancy is required, a mesh network topology may be a preferable option.

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Related Terms

• full-duplex
• patch panel
• route summarization (route aggregation)

Star Topology

In a star topology, each network node is connected to a central device called a hub or a switch. Star topologies are also commonly used with LANs.

If a cable in a star network breaks, only the node connected to that cable is isolated from the network. The other nodes can continue to operate without interruption - unless, of course, the node that is isolated because of the break happens to be the file server.

You should be aware of the somewhat technical distinction between a hub and a switch. Simply put, a hub does not know anything about the computers that are connected to each of its ports. So when a computer connected to the hub sends a packet to a computer that is connected to another port, the hub sends a duplicate copy of the packet to all its ports. In contrast, a switch knows which computer is connected to each of its ports. As a result, when a switch receives a packet intended for a particular computer, it sends the packet only to the port that the recipient is connected to.

Strictly speaking, only networks that use switches have a true star topology. If the network uses a hub, the network topology has the physical appearance of a star, but is actually a bus. That is because when a hub is used, each computer on the network sees all the packets sent over the network, just like in a bus topology. In a true star topology, as when a switch is used, each computer sees only those packets that were sent specifically to it, as well as broadcast packets that were specifically sent to all computers on the network.

Why is this relevant for C2G?

Our network cabling products - copper and fiber - provide the links between the nodes within the topology.

Overview

A network topology describes how computers, printers, and other devices (i.e. nodes) are connected to the network. The following topologies are most commonly used to build most networks.

Bus Topology

A bus topology exists when all of the nodes on the network are connected to a single cable. This single cable is commonly referred to as a backbone. Bus topology was used for early 10Base-2, ThinNet, and 10Base-5, ThickNet, coaxial cable Ethernet networks. In this topology messages sent from a node are broadcast to all nodes on the network. Only the intended recipient node accepts and processes the message. This type of network topology is relatively easy to install and inexpensive. This topology requires that both ends of the backbone cable be terminated. If the backbone is not terminated, then signal is likely to bounce back from the end of the cable causing data collisions and noise that may disrupt the network. The main drawbacks to this type of network topology are a limitation on the amount of computers that can be connected to the network, and the fact that only a single backbone cable is used to connect all of the nodes. Network using a bus topology are limited to only a few dozen computers. If the network exceeds this size performance, problems will likely result. If there is a failure in the backbone cable connecting all of the nodes, then the entire network will become unstable and potentially cease to function. This topology is not typically used in modern networks.

Georgina Guthrie in Development

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One of the first decisions you face when setting up a network is what kind of ‘topology’ to use. The network topology dictates how different sender and receiver nodes communicate with each other. Each type of topology has its advantages and drawbacks, making it important to pick the setup that provides the best performance and stability for your network. Today, we will focus on the most popular one: star topology.