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:10:7D192.168.1.10:200015:BE:9F:AB:10:1D192.168.1.14:1200
05:DD:1F:AB:10:27192.168.1.10:100022:C7:2F:AB:10:A2192.168.1.15:1300
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
Correct 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.
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. 802.11a
Correct 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.
The administrator modifies a rule on the firewall, and now all the FTP users cannot access the server any longer. The manager calls the administrator and asks what caused the extreme downtime for the server. In regards to the manager’s inquiry, which of the following did the administrator forget to do FIRST?
A. Submit a change request B. Schedule a maintenance window C. Provide notification of change to users D. Document the changes
A technician needs to secure web traffic for a new e-commerce website. Which of the following will secure traffic between a web browser and a website?
A. SSL B. DNSSEC C. WPA2 D. MTU
Correct Answer: A
Explanation: Secure Sockets Layer (SSL) provides cryptography and reliability for upper layers (Layers 5–7) of the OSI model. SSL (and TLS) provide secure web browsing (web traffic) via Hypertext Transfer Protocol Secure (HTTPS).
A network administrator is setting up a web-based application that needs to be continually accessible to the end users. Which of the following concepts would BEST ensure this requirement?
A. High availability B. Snapshots C. NIC teaming D. Cold site
The IT manager at a small firm is in the process of renegotiating an SLA with the organization’s ISP. As part of the agreement, the organization will agree to a dynamic bandwidth plan to provide 150Mbps of bandwidth. However, if the ISP determines that a host on the organization’s internal network produces malicious traffic, the ISP reserves the right to reduce available bandwidth to 1.5 Mbps. Which of the following policies is being agreed to in the SLA?
A. Session hijacking B. Blocking C. Throttling D. Data usage limits E. Bandwidth quotas
A technician has verified that a recent loss of network connectivity to multiple workstations is due to a bad CAT5 cable in the server room wall. Which of the following tools can be used to locate its physical location within the wall?
A. Cable certifier B. Multimeter C. Cable tester D. Toner probe
Correct Answer: D
Explanation: Toner probes are specifically used to trace cables hidden in floors, ceilings, or walls. They can also be used to track cables from the patch panels to their destinations.
The human resource department has been moved to an area which is more than 60 meters away from the nearest IDF. In order to comply with the SLA which requires that 10Gb speeds be provided, which of the following media will need to utilized?
Which of the following network infrastructure implementations would be used to support files being transferred between Bluetooth-enabled smartphones?
A. PAN B. LAN C. WLAN D. MAN
Correct Answer: A
Explanation: PAN stands for Personal Area Network. It is a network of devices in the area of a person typically within a range of 10 meters and commonly using a wireless technology such as Bluetooth or IR (Infra-Red).