Question 1

What is the most common cause of network connectivity issues?
A)Physical layer issues such as power outage or cable unseated
B)Corrupt NIC drivers
C)Registry values incorrect
D)Router configuration

Accepted Answer

The most common cause of loss of connectivity are issues with the physical layer.
Key Takeaway: As engineers, we sometimes tend to look more deeply than we need to. The vast majority of network connectivity issues have to do with a power outage or a cable being unseated. Always check these first! There was a network engineer who went to fix a printer that would not connect to the network. He ran all sorts of analyses on the network, the switch, the print server, and the printer, only to find out that when the client had moved the printer, they had neglected to plug the data cable back in.

Question 2

Your network design emphasizes efficient, error-free transport instead of fast transport. Which switching mode should be configured on the new switches to provide error-free transport to the network?
A)Cut-through
B)Fragment Free
C)Fast Forward
D)Store-and-forward

Accepted Answer

The switching method that provides an error-free transport is the store-and-forward method.
Key Takeaway: Store-and-forward switching refers to a technique in which frames are completely processed before being forwarded out to the appropriate port. This processing includes calculating the Cyclic Redundancy Check (CRC) and checking the destination address. In addition, frames must be temporarily stored until network resources are available to forward the message.

Question 3

Which of the following actions would increase congestion on an Ethernet network?
A)Adding hubs on the network
B)Increasing the number of collision domains
C)Putting additional switches on the network
D)Micro-segmenting the network

Accepted Answer

When more hubs are added in a network, it increases congestion on the network and the bandwidth available is divided between the different devices on the network.
Key Takeaway: Increasing the number of collision domains on the network will generally improve the performance of the network.

Question 4

Which of these traffic-shaping mechanisms sends packets at a constant rate equivalent to the size of the hole in the bucket?
A)Holey bucket
B)Leaky bucket
C)Token bucket
D)Full bucket

Accepted Answer

The leaky bucket algorithm can be used to send packets at a constant rate that is equivalent to the size of the hole in the bucket.
Key Takeaway : The leaky-bucket mechanism is used to control the rate at which traffic is sent to the network. A leaky bucket provides a mechanism by which burst traffic can be shaped to present a steady stream of traffic to the network, as opposed to traffic with erratic bursts of low-volume and high-volume flows. Token bucket is a common algorithm used to control the amount of data that is injected into a network, allowing for bursts of data to be sent.

Question 5

Which of the following is a term used to define automatic distribution of traffic over multiple links or processors to optimize responses?
A)Load balancing
B)Re-balance
C)Tuning traffic
D)Setting Traffic

Accepted Answer

Automatic distribution of traffic over multiple links to optimize responses is known as load balancing.
Key Takeaway: Load balancing is a technique where traffic on the network is automatically distributed in order to optimize resource utilization, maximize throughput, and minimize response time. It is often used to implement failover, the continuation of a service after the failure of one or more of its components.

Question 6

Which of the following features associated with a Switch helps you interconnect the switches?
A)Trunking
B)STP
C)Port mirroring
D)Cascading

Accepted Answer

You must use the Trunking feature to interconnect the switches.
Key Takeaway: Trunking allows you to connect the switches and assign one of the ports as a trunk port. The trunk port is used to carry VLAN traffic to the other switch. VLANs are allowed to contain ports from multiple switches. If data is destined for all systems in the VLAN, the VLAN identification information is added to the data packet and then the switch sends the packet out the trunk port.

Question 7

Which of the following protocols is most important for Windows Directory Services (i.e. Microsoft Domains) to function properly?
A)LDAP
B)DNS
C)DHCP
D)SNMP

Accepted Answer

LDAP, or Lightweight Directory Access Protocol, is required for distributed directories of information, such as the directory information associated with Microsoft networks.
Key Takeaway - Lightweight Directory Access Protocol allows for directory information, such as user names and roles in Microsoft. DNS (Domain Name Service) is responsible for resolving IP addresses to domain names. DHCP (Dynamic Host Configuration Protocol) provides for automatic assignment of IP addresses to clients, and SNMP (Simple Network Management Protocol) allows the monitoring of devices, such as routers and printers.

Question 8

Which of the following is the fastest method for transmitting data using a switch?
A)Store and forward
B)Fully buffered
C)Cut through
D)Loop back

Accepted Answer

The fastest among the switching methods for transmitting data through a switch is the cut-through method.
Key Takeaway: Cut through reads the frame's hardware address before starting to forward it. Store and forward buffers and performs a checksum on each frame before forwarding it on. Since there is no error checking with the cut-through method, it is significantly faster though less reliable than the store-and-forward method.

Question 9

Jack is troubleshooting a workstation that is connected to a star network. He observes that the workstation is not able to connect to the network resources. Which of the following should he check first to solve this issue?
A)The link lights on the workstation NIC
B)The link lights on the server NIC
C)The link lights on the switch
D)The NIC drivers

Accepted Answer

In this case, Jack should check the link lights on the workstation NIC.
Key Takeaway: Since the server is able to communicate with other workstations, Jack doesn't need to check the server NIC or the switch. He needs to check the link lights to see if they are stable or blinking. A stable light ensures good physical connectivity. Once the NIC is verified to be working, the NIC drivers can be checked.

Question 10

Jack is working in an organization as an IT specialist. The company's web server is undergoing a process of security and redundancy enhancement. Hence, the server is now backed up with multiple power supplies and spike protection. Which of the following would strengthen the server in terms of a high uptime?
A)Upgrading all the switches in the network to Gigabit
B)Upgrading the outbound NIC to a gigabit card
C)Installing an additional Router
D)Installing additional NICs on the server

Accepted Answer

Redundancy refers to the availability of a component to substitute for a failed component. Adding extra NICs can make it fault tolerant in terms of the network connectivity.
Key Takeaway: To increase the uptime of the server, add some more NICs with power backup systems. This ensures that a working NIC can be available at times of NIC failure.

Question 11

You are troubleshooting an issue with no connectivity through a DSL modem. Which of the following is a first step in resolving an issue?
A)Power cycling the modem
B)Identify the LEDs on the modem
C)Using ipconfig to renew all IP parameters
D)Term the modem as faulty and replace it with a working one

Accepted Answer

The first thing to check for is the LEDs on the modem. This should give you direction for how best to proceed with the fix and which component to check for errors.
Key Takeaway: A typical modem has 4 attributes: power, DSL, LAN and Internet. These are represented by 4 LEDs on the modem. Assuming that the LEDs are functioning properly, one may get something to work on once the LED status is known. For example, if the DSL LED is OFF, then try to call the DSL provider for no connectivity issues.

Question 12

While manning the help desk, you receive two calls at the same time. The first is from a user who cannot print a Word file and the second is from a user who cannot restore payroll records. How should you handle the two calls?
A)Handle both at the same time.
B)Tell them both to call back later.
C)Handle the printing problem first.
D)Handle the payroll user first.

Accepted Answer

You should handle the payroll user first since it is of higher priority.
Key Takeaway: Although both calls may seem to be of equal priority, you should help the payroll user first. Payroll issues can affect the entire workforce. Since this issue could be a serious concern, you should view this as a priority.

Question 13

Jack wants to connect his laptop to his desktop computer using a wired connection. Which of the following cable types should he use?
A)Crossover
B)Straight through
C)Direct cable
D)Rollover cable

Accepted Answer

Jack should use the crossover cable to connect the two computers (peers) with each other.
Key Takeaway: Crossover cables are very similar to straight-through cables, except that the transmit and receive wires in each pair of wires are reversed from end to end. This allows each device to receive data on each wire on which the other device is sending data. This, in turn, allows two devices to communicate via Ethernet directly without the need of an intervening switch.

Question 14

A number of employees are complaining about slow Internet connection to John, the IT supervisor. John suspects crosstalk and wants to use a cabling standard that is least susceptible to crosstalk. Which type of cabling should he use?
A)UTP
B)STP
C)Fiber optic
D)Coaxial

Accepted Answer

Fiber optic cabling is least susceptible to cross talk, even though the cables run beside each other.
Key Takeaway: Crosstalk (XT) refers to any phenomenon by which a signal transmitted on one circuit or channel of a transmission system creates an undesired effect on another circuit or channel. Crosstalk is usually caused by undesired capacitive, inductive, or conductive coupling from one circuit. Fiber-optic communication is a method of transmitting information from one place to another by sending pulses of light through an optical fiber. An optical fiber consists of a core, cladding, and a buffer (protective outer coating), in which the cladding guides the light along the core by using total internal reflection. Proper thickness of the cladding ensures elimination of crosstalk.

Question 15

You head the network support team at your organization. Which of the following problems would you assign as the highest priority for your network support team?
A)Print server failure in the sales department
B)The corporate e-mail server is down
C)Installing software in employees' PCs
D)A malfunctioning hub in the engineering department

Accepted Answer

Of all the problems mentioned here, the highest priority should go to the fixing the corporate e-mail server.
Key Takeaway - A print server failure, software installation, and a malfunctioning hub may only partially obstruct the smooth functioning of an organization. However, a malfunctioning e-mail server hinders all official mail communication. It should be attended to first.

Question 16

What should you do to ensure that TCP/IP is bound properly to the NIC and the NIC drivers are working properly?
A)Ping 10.10.10.10
B)Ping 127.0.0.1
C)Ping 127.0.0.0
D)Ping 255.255.255.255

Accepted Answer

To check that TCP/IP is bound to the NIC properly or to check the integrity of the NIC, ping the loopback address, which is 127.0.0.1. This pings the device's own network adapter as if it were a different system.
Key Takeaway: This is known as the loopback test. A successful ping request to 127.0.0.1 will verify that a computer's network interface card, its drivers, and the operating system's TCP/IP implementation are all functioning correctly.

Question 17

John is working in the Network repair and troubleshooting unit with a DSL service provider. He is trying to fix an issue with packets being lost en route to the destination. Which of these utilities can be used to find the number of hops a packet takes from the source to the destination?
A)tracert
B)nbtstat
C)ns lookup
D)netstat

Accepted Answer

Tracert is the network troubleshooting tool that displays the number of hops taken by a packet from the source to the destination. The syntax for a tracert command for Windows is tracert host name .The command on Unix/Linux machines is traceroute hostname.
Key Takeaway: Tracert is the most used command for network troubleshooting under conditions of intermittency or packet loss. The timing information from tracert can be useful for detecting a malfunctioning or overloaded router.

Question 18

Jack is working on a Linux system and wants to perform a manual DNS lookup. Which of the utilities should he use?
A)netstat
B)mtr
C)route
D)dig

Accepted Answer

The dig command is used to troubleshoot DNS problems because of its flexibility, ease of use, and clarity of output.
Key Takeaway: Dig is a tool for querying DNS nameservers for information about host addresses, mail exchanges, nameservers, and related information. This tool can be used from any Linux, Unix, or Macintosh OS X operating system. The most typical use of dig is simply to query a single host. Netstat is a useful tool for checking your network configuration and activity. Mtr combines traceroute and ping into a single network diagnostic tool. Route command is used to add and delete routes.

Question 19

You need to find out the name of a host using an IP address on the Internet. Which of the following will provide the name?
A)Tracert
B)Netstat
C)Ipconfig
D)Nslookup

Accepted Answer

Nslookup is a command-line administrative tool used to test and troubleshoot DNS servers.
Key Takeaway: Ns lookup is used in Windows and Unix to query Domain Name System (DNS) servers to find DNS details, including IP addresses of a particular computer, MX records for a domain, and the NS servers of a domain. Ipconfig merely displays the IP parameters. Tracert gives the number of hops to reach the destination. Netstat is a useful tool for checking your network configuration and activity.

Question 20

Jack has installed fiber optic cabling in his office. However, he is not able to utilize the capabilities of the fiber optic setup and suspects multiple light losses. Which of the following network troubleshooting tools can he use to verify this?
A)Multimeter
B)Cable tester
C)Protocol analyzer
D)OTDR

Accepted Answer

To detect any light losses in the fiber optic cabling setup, Jack should use an OTDR.
Key Takeaway: Optical time-domain reflectometer (OTDR) is an optoelectronic instrument used to characterize an optical fiber. An OTDR injects a series of optical pulses into the fiber. From the same end of the fiber, it also extracts light that is scattered and reflected back from points in the fiber where the index of refraction changes.

Quiz 22: Management

What is the most common cause of network connectivity issues?

Your network design emphasizes efficient, error-free transport instead of fast transport. Which switching mode should be configured on the new switches to provide error-free transport to the network?

Which of the following actions would increase congestion on an Ethernet network?

Which of these traffic-shaping mechanisms sends packets at a constant rate equivalent to the size of the hole in the bucket?

Which of the following is a term used to define automatic distribution of traffic over multiple links or processors to optimize responses?

Which of the following features associated with a Switch helps you interconnect the switches?

Which of the following protocols is most important for Windows Directory Services (i.e. Microsoft Domains) to function properly?

Which of the following is the fastest method for transmitting data using a switch?

Jack is troubleshooting a workstation that is connected to a star network. He observes that the workstation is not able to connect to the network resources. Which of the following should he check first to solve this issue?

You are troubleshooting an issue with no connectivity through a DSL modem. Which of the following is a first step in resolving an issue?

While manning the help desk, you receive two calls at the same time. The first is from a user who cannot print a Word file and the second is from a user who cannot restore payroll records. How should you handle the two calls?

Jack wants to connect his laptop to his desktop computer using a wired connection. Which of the following cable types should he use?

A number of employees are complaining about slow Internet connection to John, the IT supervisor. John suspects crosstalk and wants to use a cabling standard that is least susceptible to crosstalk. Which type of cabling should he use?

You head the network support team at your organization. Which of the following problems would you assign as the highest priority for your network support team?

What should you do to ensure that TCP/IP is bound properly to the NIC and the NIC drivers are working properly?

John is working in the Network repair and troubleshooting unit with a DSL service provider. He is trying to fix an issue with packets being lost en route to the destination. Which of these utilities can be used to find the number of hops a packet takes from the source to the destination?

Jack is working on a Linux system and wants to perform a manual DNS lookup. Which of the utilities should he use?

You need to find out the name of a host using an IP address on the Internet. Which of the following will provide the name?

Jack has installed fiber optic cabling in his office. However, he is not able to utilize the capabilities of the fiber optic setup and suspects multiple light losses. Which of the following network troubleshooting tools can he use to verify this?