Chapter 1: Introduction to Networking

What type of cable is used when utilizing a cable modem, or a DSL modem?

A cable modem uses coax, whereas DSL uses RJ-11.

What is a client/server network?

A client/server model is most commonly found in all businesses, especially those large in size, and vast in wealth. A core advantage this network provides is centralized network management, including user control, security, and backup procedures. This is the most optimal method when creating an IT solution.

What is a star topology?

A star topology is where all devices on a network connect to a central device such as a hub, or a switch. Each device requires a single cable to be connected to the central hardware, creating a point-to-point connection.

What is a core disadvantage to a star topology?

A star topology relies on a single device to service all connected computers. Therefore, this single point of failure would cause issues in the event a hub or switch failed.

What is a topology?

A topology refers to the physical, and logical layout of a network. The physical layout refers to where cabling, and devices are located throughout the building. The logical layout refers to the way in which the network appears to the devices using it.

With which topology does every node have a direct connection to every other node?

Mesh

What are three popular technologies used to connect to the Internet?

1. DSL 2. Cable modem 3. Fiber (FiOS)

What are the seven main requirements to think of when designing a network from scratch?

1. List of requirements. This is regarding permissions, file access, printer devices on the network, etc. 2. Device types/requirements: Money always influences decision making for hardware. Determining the best bang for your buck is vital. 3. Environment limitations: If your building is old, and made of cinderblock and rebar, wireless would not be the best choice lest you install an access point outside every door. 4. Equipment limitations: Routers, switches, and so on have port limitations based on size. Working within said limitations is important when drafting a network solution. 5. Compatibility requirements: There are some devices, protocols, or software that are incompatible with others due to it being proprietary. Ensuring there is an open standard helps with the integration of new equipment. 6. Wired/wireless considerations: Both technologies have limitations that need to be considered. Wireless can be restricted based off of distance or interference via building material. Wired on the other hand can be limited based off of distance, but more importantly have to be within building spec. For example, cabling if burned releases toxic chemicals in the air that could transport along with the spread of smoke. So, if a fire broke out, this could spell disaster. As such, riser cable between floors is the perfect choice because it's flame retardant. This helps alleviate this issue, while also being capable of handling higher temperature environments. 7. Security considerations: This is an extremely important aspect no matter who, what, when, where, or why. Security is an ever-growing technology field, and should be at the forefront of every business.

What are three core disadvantages to a bus topology?

1. Network disruption can occur as the number of computers grow. 2. If a break occurred in the cable, that would bring down the entire network, causing all computers connecting to the backbone to lose its ability to communicate to one another. 3. Troubleshooting a bus topology is difficult.

What is the four or five typical sequence of lights on a cable modem?

1. Power 2. Receive 3. Send 4. Online 5. Activity

What is the maximum number of computers recommended for inclusion in a peer-to-peer network? A. 2 B. 5 C. 10 D. 25

10

What is a LAN?

A LAN is a local area network that is restricted to a single site for the purpose of file sharing, network communication, and so on.

What is a MAN?

A MAN is similar to a WAN, but rather than being spread out to different locations all across the State, Country, or World, it is confined to a certain area, such as a University campus or city.

What is a PAN?

A PAN is similar to a LAN, but very strict in distance. For example, close proximity technologies such as Bluetooth, NFC, or Infrared would be used for exchanging data. Another term for this would be ad-hoc wireless networking, where devices connect to each other directly, rather than through a router, or wireless access point.

What is a point-to-multipoint wireless network?

A PtMP wireless network is designed to link multiple wired networks. The wireless signal in a PtMP network travels from a central node such as a base station of a cellular system, an access point of a WLAN, or a satellite. This is where said base station connects to client networks. PtMP networks are used in WISP's, large corporate campuses, interconnected branch offices, and more.

What is a SCADA or ICS?

A SCADA/ICS system is one comprised of non-typical remote equipment. A good example would be pumping stations, robotic machines, and so on. The SCADA/ICS would be the operating system. That said, a typical configuration includes an ICS server, DCS devices creating a closed network, a remote terminal unit, and a programmable logic controller. In short, SCADA/ICS systems are often used to gather information from remote systems in real time.

What is a WAN?

A WAN is a wide area network that spans more than one geographic site, often interconnecting separated LAN's. This is accomplished through Service Providers who own leasing rights to different locations. These areas then have Infrastructure with cabling underneath concrete to interconnect sites.

What is a bus topology?

A bus topology involves a backbone which enables all computers to connect to the network. A old school example would include wiring, and T-connectors, also known as vampire taps as you must pierce the wire to receive an electrical connection. Now, to avoid signal reflection, a physical bus topology requires each end of the bus to be terminated, with one end also being grounded.

What is a hybrid mesh network?

A hybrid mesh is similar to a full mesh, where only specific devices such as servers get full redundancy. That way you get the benefit of full mesh, while negating the complexity and costs associated with a full mesh design.

What does a hybrid topology refer to?

A hybrid topology can refer to the combination of wireless and wired networks. Or, it is referring to the combination of different topologies, such as star, bus, ring, mesh, etc.

What is the purpose of a wired mesh topology?

A mesh topology design provides a high level of redundancy. Therefore, if one cable fails, the data traversing the network always has an alternative path to get to its destination; each node can act as a relay.

In a ring network, what device is the equivalent to a hub or switch on an Ethernet network?

A multi-station access unit (MSAU) is. This devices performs the token circulation internally. To create a complete ring, the ring-in (RI) port on each MSAU is connected to the ring-out (RO) port on another MSAU. The last MSAU in the ring is then connected to the first to complete the ring.

What network model offers no centralized storage of data or centralized control over the sharing of files or resources?

A peer-to-peer network is a decentralized network model offering no centralized storage of data or centralized control over the sharing of files or resources.

What is a peer-to-peer network?

A peer-to-peer network is decentralized, offering no central access, control, or storage of shared files. This type of network is most suitable when financial concerns are at play, rather than opting for a client/server environment. For example, a small office, home, or mom and pop shop. The recommended rule of thumb is to have no more than ten computers on a decentralized model.

What are the benefits, and disadvantages of wireless, and wired meshing?

A positive of wireless meshing is that it is cheap and inexpensive whereas a wired mesh solution is not only often messy, but costly due to the sheer number of cables.

What is a ring topology?

A ring topology is not a physical ring, but rather a logical ring, meaning the data travels in a circular fashion from one computer to another on the network. In a true ring topology, if a single computer or a section of cable fails, the entire network becomes inaccessible. But, there are fault-tolerant designs with the inclusion of additional rings. Naturally, this increases the cost and complexity of the network.

What's the difference between a wall jack and a surface jack?

A wall jack is where you run traditional cabling through the wall, and use the wall jack for wired connectivity. A surface jack on the other hand allows you to run wire on the outside of the wall.

What is a wireless mesh network?

A wireless mesh design, similarly to a wired mesh interconnects all wireless access points together to increase redundancy.

What's another name for an unmanaged wireless network?

Ad hoc

Which of the following is a remote system used to gather and analyze data in real time? A. Client/server B. Centralized C. Distributed D. SCADA/ICS

SCADA/ICS

What is a wireless ad hoc topology?

Ad hoc refers to devices that communicate directly between themselves without the assistance of an access point. An example of ad hoc would be connecting mobile devices together or a printer using Bluetooth. Or, you may need to briefly connect several laptops and a single printer together to share, and print files. This would also be an ad hoc network.

Which of the following are major requirement considerations when implementing a basic network? (Choose all correct answers.) a. Security considerations b. Device types c. Equipment limitations d. Compatibility requirements

All of thee above

What is a point-to-point wireless network?

An example of a wireless P2P network would be where two access points directly connect to one another, allowing communication between distinct networks. The connection between two access points would be a replacement for a single wired connection where distance or physical terrain may impose design issues.

What is the purpose of a managed wireless network?

Central control, and the ability to form a bridge between wireless and wired LAN's. Access points are not mobile, and require a wired connection; therefore becoming part of the wired network infrastructure.

What is a Medianet?

Cisco has created architecture that can look at a variety of media available, and choose what combination is best given the available applications. For example, a medianet can be useful with video teleconferencing, and is often used with SIP which runs over IP, and is associated with ISDN.

What is a variation to a full mesh network?

Hybrid mesh, also known as a partial mesh.

When a WAN is confined to a certain geographic area, such as a university campus or city, it is known as a what? A. LAN B. MAN C. VAN D. VPN

MAN

What are the two different types of wireless topologies?

Managed and unmanaged

What's the primary difference between pre-fab ethernet cabling, and do-it yourself cabling?

Pre-fab comes in common sizes, such as 5, 10, 15, 50 and 100 feet. It also tends to be more expensive due to the work already being performed. On the flipside, buying cable in bulk helps save in cost, and as such, you can create more accurate length cabling to fit your business needs. The major cost in this case would be man-hours since you're expensing a technician to be meticulous.

On a typical cable modem, which panel light is found next to or beneath the power light?

Receive. The reason being, after you've confirmed your modem is receiving power, then it should receive an active connection flowing into your modem from the Service Provider.

Which topology (star, bus, or ring) would utilize a switch?

Star

Ring networks are most commonly wired in what topology configuration?

Star topology

What is a point of demarcation?

The demarc is the point where the Service Provider stops being responsible for the line, and it becomes your responsibility. This tends to be the box on the outside of your home or business with wiring poking out.

What is the point of demarcation with a small office?

The point of demarcation is always the point where the service provider stops being responsible for the wiring and it becomes your responsibility.

What is the difference between centralized and distributed computing?

The primary difference between centralized or distributed is the location where processes take place. For example, in a centralized model, you may have mainframes that provide resources whereas dumb terminals are incapable of storage and processing data. A distributed network on the other hand is most commonly associated with client/servers. Client devices in this case share responsibilities with servers.

What is a wired mesh topology?

This topology is unique, where each computer on the network connects to every other, creating a point-to-point connection between every device on the network.

True or False: The biggest difference between a LAN and WAN is usually the size of the network.

True. A WAN is a network that spans more than one geographic location, often connecting separated LANs.

True or false? Cable modems and DSL modems are commonly used in SOHO implementations for Internet access?

True. Cable modems and DSL modems are user-friendly, therefore they are both perfect for a small office - home office environment.

What is the core benefit to using a star topology?

You can add devices, and expand your network without disruption to other devices due to there being only a single fault per P2P connection.

Which of the following statements are associated with a bus LAN network? (Choose all correct answers.) a. A single cable break can cause complete network disruption. b. All devices connect to a central device. c. It uses a single backbone to connect all network devices. d. It uses a dual-ring configuration.

a. A single cable break can cause complete network disruption. c. It uses a single backbone to connect all network devices.

You have been asked to connect two office locations. It has been specified that a wireless link be used. Which of the following strategies would you use to connect the two offices? a. Point-to-point b. Wireless mesh c. PtMP d. Star bus hybrid

a. Point-to-point

Which network topology offers the greatest level of redundancy but has the highest implementation cost? a. Wireless mesh b. Wired mesh c. Hybrid star d. Bus network

b. Wired mesh

As a network administrator, you are called in to troubleshot a problem on a token ring network. The network uses two MSAUs connected using the ring-in ports on both devices. All network cards are set at the same speed. What is the likely cause of the problem. a. Bad network card b. Faulty cabling c. MSAU configuration d. Network card configuration

c. MSAU configuration

You have been asked to install a network that will give the network users the greatest amount of fault tolerance. Which of the following network topologies would you choose? a. Star b. Ring c. Mesh d. Bus

c. Mesh

Which of the following is true of many SOHO routers? a. They close down the DHCP ports by default. b. They close down the NAT ports by default. c. They close down the ICMP ports by default. d. They leave open the DHCP, NAT, and ICMP ports by default.

c. They close down the ICMP ports by default.

What topology is represented in the following figure? The following figure has two workstations interconnected via a switch, with the third port connected to a wireless access point. The access point is then connecting two laptops. a. Star topology b. Star bus c. Ad hoc d. Infrastructure

d. Infrastructure

Which of the following topologies allows for network expansion with the least amount of disruption for the current network users? a. Bus b. Ring c. LAN d. Star

d. Star