- (Exam Topic 3)
Due to concerns around single points of failure, a company decided to add an additional WAN to the network. The company added a second MPLS vendor to the current MPLS WAN and deployed an additional WAN router at each site. Both MPLS providers use OSPF on the WAN network, and EIGRP is run internally. The first site to go live with the new WAN is successful, but when the second site is activated significant network issues occur. Which of the following is the MOST likely cause for the WAN instability?
Correct Answer:B
Asymmetrical routing is the most likely cause for the WAN instability. When two different routing protocols are used, like OSPF and EIGRP, it can cause asymmetrical routing, which results in traffic being routed differently in each direction. This can lead to instability in the WAN. A CDP neighbor change, a switching loop, or an incorrect IP address are not likely causes for WAN instability.
- (Exam Topic 3)
A network administrator needs to configure a server to use the most accurate NTP reference available. Which of the following NTP devices should the administrator select?
Correct Answer:A
Stratum 1 devices are the most accurate ntp time sources accessible via a network connection. A Stratum 1
device would normally be synchronised via a Stratum 0 reference clock. Reference: https://endruntechnologies.com/products/ntp-time-servers/stratum1
- (Exam Topic 2)
Which of the following security devices would be BEST to use to provide mechanical access control to the MDF/IDF?
Correct Answer:D
A door lock would be the best security device to use to provide mechanical access control to the MDF/IDF. A door lock is a device that prevents unauthorized access to a physical area by requiring a key, a code, a card, a biometric scan, or a combination of these factors to open it. A door lock can provide mechanical access control to the MDF/IDF, which are rooms that house network equipment such as switches, routers, servers, or patch panels. A door lock can prevent unauthorized persons from tampering with or stealing the network equipment or data. References: https://www.cisco.com/c/en/us/td/docs/solutions/Enterprise/Data_Center/DC_Infra2_5/DCInfra_6.html
- (Exam Topic 2)
An IT technician suspects a break in one of the uplinks that provides connectivity to the core switch. Which of the following command-line tools should the technician use to determine where the incident is occurring?
Correct Answer:D
show interface is a command-line tool that displays information about the status, configuration, and statistics of an interface on a network device. A technician can use show interface to determine where the incident is occurring in a network by checking the uplink status, speed, duplex mode, errors, collisions, and other parameters of each interface. References: https://www.comptia.org/blog/what-is-show-interface
- (Exam Topic 3)
A network administrator needs to monitor traffic on a specific port on a switch. Which of the following should the administrator configure to accomplish the task?
Correct Answer:C
Port mirroring is a feature that allows a network technician to monitor traffic on a specific port on a switch by copying all the traffic from that port to another port where a monitoring device is connected. Port mirroring can be used for troubleshooting, analysis, or security purposes, such as detecting network anomalies, performance issues, or malicious activities. References:
https://www.comptia.org/training/books/network-n10-008-study-guide (page 156)