Topic 5: Industry Standards, Practices, and Network Theory Flashcards
When a client calls and describes a problem with a computer not being able to reach the Internet, in which of the following places of the OSI model would a technician begin troubleshooting? A. Transport layer B. Physical layer C. Network layer D. Session layer
Answer: B
Explanation: The bottom layer of the OSI reference model is Layer 1, the physical layer. The physical layer is the layer that defines the hardware elements of a network. These elements include: When troubleshooting a network connectivity issue, the first thing you would check is the computer’s network cabling, the network card etc. In other words, the computer’s physical connection to the network.
A network engineer is dispatched to an employee office to troubleshoot an issue with the employee's laptop. The employee is unable to connect to local and remote resources. The network engineer flips the laptop's wireless switch on to resolve the issue. At which of the following layers of the OSI model was the issue resolved? A. Layer 1 B. Layer 2 C. Layer 3 D. Layer 4 E. Layer 7
Answer: A
Explanation: The bottom layer of the OSI reference model is Layer 1, the physical layer. The physical layer is the layer that defines the hardware elements of a network. These elements include: In this question, the network engineer flipped the laptop’s wireless switch on to resolve the issue. The laptop was unable to connect to the wireless network because the wireless network interface card was switched off. Switching the wireless network interface card on enabled the laptop to connect to the wireless network. The wireless network interface card is a physical layer device.
When troubleshooting a network problem, browsing through the log of a switch, it is discovered that multiple frames contain errors. In which of the following layers does the problem reside? (Select TWO). A. Layer 2 B. Layer 3 C. Layer 5 D. Transport layer E. Data link F. Physical layer
Answer: A,E
Explanation: Layer 2 of the OSI reference model is the data-link layer. Components of the data-link layer include frame-format, Media Access Control (MAC) addressing, protocol identification and error detection. When data is being sent, it is split into protocol data units (PDUs) as it passes through the layers of the OSI model. The PDUs have different names as they are passed through the layers of the OSI model. In layer 2, the PDU is called a ‘Frame’. The most common protocol specified in the data-link layer is Ethernet and the most common network component in the data-link layer is a network switch. In this question, problems are discovered with Ethernet frames by examining the logs in a network switch. Therefore, for this question, we are working in Layer 2, the data-link layer.
A network administrator is using a packet analyzer to determine an issue on the local LAN. Two separate computers are showing an error message on the screen and are unable to communicate with other computers in the same lab. The network administrator looks at the following output: SRC MAC SRC IP DST MAC DST IP 00:1D:1F:AB:10:7D 192.168.1.10:2000 15:BE:9F:AB:10:1D 192.168.1.14:1200 05:DD:1F:AB:10:27 192.168.1.10:1000 22:C7:2F:AB:10:A2 192.168.1.15:1300 Given that all the computers in the lab are directly connected to the same switch, and are not using any virtualization technology, at which of the following layers of the OSI model is the problem occurring? A. Network B. Application C. Data link D. Transport
Answer: A
Explanation: If we look at the Source Mac column, we can see two different MAC addresses. Every network interface card has a unique MAC address. These are the network cards in the two separate computers. If we look in the Source IP column, we can see that the two network cards have been assigned the same IP address (192.168.1.10). This is the problem in this question. The error message on the screens will be saying that “An IP conflict exists”. Every network card connected to the network needs to be configured with a different IP address. As the problem is with the IP address configuration of the two computers, we know that the problem is occurring at the Network layer (layer 3) of the OSI model. The network layer is responsible for Internet Protocol (IP) addressing and routing.
Which of the following will negotiate standoff timers to allow multiple devices to communicate on congested network segments? A. CSMA/CD B. OSPF C. DOCSIS D. BGP
Answer: A
Explanation: Carrier Sense Multiple Access/Collision Detect (CSMA/CD) is used by devices in an Ethernet network for transmitting data on the network. Any device on an Ethernet network can send data at any time. The network devices sense when the line is idle and therefore available for the transmission of data. The network device then transmits a data frame onto the network. If another device sends a frame at exactly the same time, a collision occurs and the frames are discarded. The network devices will then wait for a random period of time before attempting to send the frame again.
Which of the following devices implements CSMA/CA virtually through the RTS/CTS protocols? A. Firewall B. Router C. 802.11 AP D. Switch
Answer: C
Explanation: 802.11 AP is a Wireless Access Point used in a wireless network. If two computers on a network send data frames at the same time, a collision between the frames can occur. The frames are then discarded and the sending computers will attempt to send the data again. Carrier sense multiple access with collision avoidance (CSMA/CA) is a protocol used in wireless networks where computers connected to the wireless network attempt to avoid collisions by transmitting data only when the channel is sensed to be “idle”. Carrier Sense Multiple Access/Collision Detect (CSMA/CD) is unreliable in wireless networks because computers connected to the wireless network often cannot see each other so CSMA/CA is a better option for avoiding collisions. Request to Send/Clear to Send (RTS/CTS) can also be used to mediate access to the wireless network. This goes some way to alleviating the problem of computers not being able to see each other because in a wireless network, the Wireless Access Point only issues a “Clear to Send” to one node at a time. With RTS/CTS, a Request to Send (RTS) packet is sent by the sending computer, and a Clear to Send(CTS) packet is sent by the intended receiver. This will alert all computers within range of the sender, receiver or both, to not transmit for the duration of the transmission. This is known as the IEEE 802.11 RTS/CTS exchange.
The management team wants to set up a wireless network in their office but all of their phones operate at the 2.4 GHz frequency. They need a wireless network that would be able to operate at a higher frequency than their phones. Which of following standards should be used? A. 802.11a B. 802.11b C. 802.11g D. 802.1x
Answer: A
Explanation: In this question, we need a wireless network that operates at a frequency higher than the 2.4GHz frequency. 802.11 is a set of IEEE standards that govern wireless networking transmission methods. The 802.11 standards commonly used today to provide wireless connectivity in home or office wireless networks are 802.11a, 802.11b, 802.11g, 802.11n and 802.11ac. The 802.11a standard supports speeds up to 54Mbps and uses the 5-GHzband.
A user with an 802.11n WLAN card is connected to a SOHO network and is only able to connect at 11 Mbps with full signal strength. Which of the following standards is implemented on the network? A. 802.11a B. 802.11ac C. 802.11b D. 802.11g
Answer: C
Explanation: 802.11 is a set of IEEE standards that govern wireless networking transmission methods. The 802.11 standards commonly used today to provide wireless connectivity in home or office wireless networks are 802.11a, 802.11b, 802.11g, 802.11n and 802.11ac. 802.11b supports speeds up to 11Mbps and uses the 2.4GHz frequency. In this question, the user is using an 802.11n WLAN card. Although the 802.11n WLAN card can support speeds up to 300Mbps, the user is only able to connect at 11Mbps because the user is connected to a wireless network configured to use 802.11b.
A network technician has been tasked with designing a WLAN for a small office. One of the requirements of this design is that it is capable of supporting HD video streaming to multiple devices. Which of the following would be the appropriate wireless technology for this design? A. 802.11g B. 802.11ac C. 802.11b D. 109 802.11a
Answer: B
Explanation: In this question, we need a wireless network capable of supporting HD video streaming to multiple devices. We therefore need the fastest wireless network speed available. 802.11 is a set of IEEE standards that govern wireless networking transmission methods. The 802.11 standards commonly used today to provide wireless connectivity in home or office wireless networks are 802.11a, 802.11b, 802.11g, 802.11n and 802.11ac. The 802.11ac standard is the fastest wireless network supporting speeds of over 3Gbps and uses the 5-GHz band.
A company is deploying a new wireless network and requires 800Mbps network throughput. Which of the following is the MINIMUM configuration that would meet this need?
A. 802.11ac with 2 spatial streams and an 80MHz bandwidth
B. 802.11ac with 3 spatial streams and a 20MHz bandwidth
C. 802.11ac with 3 spatial streams and a 40MHz bandwidth
D. 802.11ac with 4 spatial streams and a 160MHz bandwidth
Answer: A
Explanation: Spatial streaming is used in wireless communications where multiple-input-multiple-output (MIMO) is being used. With MIMO, multiple antennas are used for transmission and reception. MIMO was available in 802.11n but its capabilities have been extended in 802.11ac. 802.11ac supports a mandatory 80 MHz channel bandwidth for stations (vs. 40 MHz maximum in 802.11n), 160 MHz available optionally and more (up to 8) special streams. A single antenna and 80 MHz channel bandwidth provides a bandwidth of 433Mbps. In this question, we need a minimum bandwidth of 800Mbps. Two antennas and 80 MHz channel bandwidth provides a bandwidth of 867Mbps and therefore meets the requirement.
A network technician is attempting to connect a new host to existing manufacturing equipment on an Ethernet network. The technician is having issues trying to establish communication between the old equipment and the new host. The technician checks the cabling for breaks and finds that the CAT3 cable in use is in perfect condition. Which of the following should the technician check to ensure the new host will connect?
A. Confirm the new host is using 10GBaseSR due to the manufacturing environment
B. Confirm the new host is compatible with 10BaseT Ethernet
C. Confirm the existing 10Base2 equipment is using the proper frame type
D. Confirm that CSMA/CD is disabled on the Ethernet network
Answer: B
Explanation: The question states that the equipment is old and that CAT3 cabling is being used. 10BaseT Ethernet networks are old and slow by today’s standards. 10BaseT Ethernet networks use CAT3 UTP cabling and offer a maximum bandwidth of just 10Mpbs. A new host computer nowadays will have a network card that supports 1000Mpbs to be used with CAT5, CAT5e or CAT6 network cables in a 1000BaseT network. In this question, we need to check that the network card on the new host computer is backward-compatible with the old 10BaseT network.
Before logging into the company network, users are required to sign a document that is to be stored in their personnel file. This standards and policies document is usually called which of the following? A. SOP B. BEP C. AUP D. SLA
Answer: C
Explanation: AUP stands for Acceptable Use Policy. An Acceptable Use Policy defines what a user can or cannot do with his or her computer during business hours. For example, using the company’s Internet connection to look at the sports scores on a sports website may be deemed inappropriate or unacceptable during business hours. Other examples include the use of social media websites such as Facebook or using Instant Messaging clients to chat to your friends.
The service provider could be in violation of the: A. MLA. B. SLA. C. SOW. D. MOU.
Answer: B
Explanation: SLA stands for Service Level Agreement. This is a common document in business used to define a minimum standard of service that a customer can expect from a supplier. SLA’s are particularly common in the I.T. sector where a service provider is offering a service to a customer. As a customer, you want your hosted services and Internet or WAN connections to be available all the time. SLAs often guarantee 99.9% uptime for a service. In this question, the service provider is providing WAN links to remote sites with a guaranteed bandwidth on the WAN links. A failure to maintain the connectivity to the remote sites would be a violation of the Service Level Agreement (SLA).
A customer has engaged a company to improve the availability of all of the customer's services and applications, enabling the customer to minimize downtime to a few hours per quarter. Which of the following will document the scope of the activities the company will provide to the customer, including the intended outcomes? A. MLA B. MOU C. SOW D. SLA
Answer: C
Explanation: SOW stands for Statement of Work. When a company has been hired for a project that involves many tasks, a statement of work is often issued at the start of the project. The SOW will outline the tasks or activities in a project, their costs and the timelines for deliverables within the project. In an IT project, the SOW would define what tasks will be performed (hardware and software upgrades etc.), why the work is being done and how long each stage of the project will take.
A technician has prolonged contact with a thermal compound. Which of the following resources should be consulted? A. HCL B. MSDS C. SLA D. HVAC
Answer: B
Explanation: MSDS stands for Material Safety Data Sheet. An MSDS is a health and safety document that contains information on the potential hazards of working with a chemical product and how to work safely with the chemical product. In this question, the thermal compound is a chemical product so the MSDS will provide information about the effects of prolonged contact with the thermal compound.
