Cisco Updated 350-401 Exam Questions and Answers by noelle

 Stratum levels indicate the distance of a network device from an authoritative time source in the Network Time Protocol (NTP) hierarchy. A Stratum 1 device is directly connected to an authoritative time source, such as a GPS or radio clock, making it the most accurate time server available to clients. Higher stratum levels (e.g., Stratum 2, Stratum 3, etc.) are further away from the authoritative source and thus have slightly less accuracy due to network delays. 

Access to Cisco DNA Center CLI is required when upgrading the Cisco DNA Center software. The CLI provides a direct interface to the underlying system, allowing for detailed control and monitoring of the upgrade process. It is essential for executing commands that may not be available through the graphical user interface (GUI), ensuring a precise and controlled software upgrade. References: The official Cisco documentation outlines the procedure for upgrading Cisco DNA Center software via CLI, detailing the necessary steps and precautions to take during the process

 In the given scenario, traceroute fails from R1 to R3 due to a lack of route information for reaching R3. This is because redistribution of connected routes into OSPF has not been configured, leading to an absence of necessary routing information in OSPF’s link-state database for establishing a complete path from R1 to R3. References: Implementing and Operating Cisco Service Provider Network Core Technologies (SPCOR)

The power difference in dBm can be calculated using the formula:

10×log10​(P1P2​)

where (P1) and (P2) are the initial and final power levels in milliwatts (mW). So, for an increase from 25 mW to 100 mW, the calculation is

10×log10​(25100​)=10×log10​(4)=10×0.6=6dBm

However, since the question asks for the difference, we need to consider that dBm is a logarithmic unit, so we use the formula for power ratio in dB which is

10×log10​(PowerRatio)

The power ratio here is

25mW100mW​=4

Therefore,

10×log10​(4)=10×0.6=6dBm

But this is the increase for each doubling of power. Since we are increasing from 25 mW to 100 mW, which is a fourfold increase or two doublings (25 mW to 50 mW to 100 mW), we have two increments of 6 dBm, which gives us a total increase of 12 dBm.However, the closest answer to 12 dBm is 17 dBm, which is answer C.References: Implementing and Operating Cisco Service Provider Network Core Technologies (SPCOR) training materials