350-401 Online Practice Questions and Answers

Correct Answer: A

Correct Answer: C

Correct Answer: B

Correct Answer: A

Correct Answer: B

Correct Answer: C

Path cost from ALSW1 to root bridge(DSW2) via DSW1 is 2 + 2 = cost of 4. ( 10gbps+10Gbps)

Path cost from ALSW1 to root bridge(DSW2) is 4 = cost of 4. ( 1Gbps)

Therefore the patch cost equal and DSW2 is root bridge Therefore it will via Gi0/2.

Answer is C.

IF let say the question change the ALSW1 to DSW2 Gi0/2 interface to 100Mbps (cost=19) , the answer will be different.

ALSW1 to DSW2 will be blocked.

Answer will be D.

Correct Answer: D

https://ultraconfig.com.au/blog/restconf-tutorial-everything-you-need-to-know-about-restconf-in-2020/

Correct Answer: E

Weighted Random Early Detection (WRED) is just a congestion avoidance mechanism. WRED drops packets selectively based on IP precedence. Edge routers assign IP precedences to packets as they enter the network. When a packet

arrives, the following events occur:

The average queue size is calculated.

2.

If the average is less than the minimum queue threshold, the arriving packet is queued.

3.

If the average is between the minimum queue threshold for that type of traffic and the maximum threshold for the interface, the packet is either dropped or queued, depending on the packet drop probability for that type of traffic.

4.

If the average queue size is greater than the maximum threshold, the packet is dropped. WRED reduces the chances of tail drop (when the queue is full, the packet is dropped) by selectively dropping packets when the output interface begins to show signs of congestion (thus it can mitigate congestion by preventing the queue from filling up). By dropping some packets early rather than waiting until the queue is full, WRED avoids dropping large numbers of packets at once and minimizes the chances of global synchronization. Thus, WRED allows the transmission line to be used fully at all times. WRED generally drops packets selectively based on IP precedence. Packets with a higher IP precedence are less likely to be dropped than packets with a lower precedence. Thus, the higher the priority of a packet, the higher the probability that the packet will be delivered. Reference: https://www.cisco.com/c/en/ us/td/docs/ios-xml/ios/qos_conavd/ configuration/15- mt/qos-conavd-15-mt-book/qos-conavd-cfg-wred.html WRED is only useful when the bulk of the traffic is TCP/IP traffic. With TCP, dropped packets indicate congestion, so the packet source will reduce its transmission rate. With other protocols, packet sources may not respond or may resend dropped packets at the same rate. Thus, dropping packets does not decrease congestion. Reference: https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/qos_conavd/ configuration/xe- 16/qos- conavd-xe-16-book/qos-conavd-oview.html Note: Global synchronization occurs when multiple TCP hosts reduce their transmission rates in response to congestion. But when congestion is reduced, TCP hosts try to increase their transmission rates again simultaneously (known as slow-start algorithm), which causes another congestion. Global synchronization produces this graph:

Correct Answer: DE

IP SLAs allows Cisco customers to analyze IP service levels for IP applications and services, to increase productivity, to lower operational costs, and to reduce the frequency of network outages. IP SLAs uses active traffic monitoringhe generation of traffic in a continuous, reliable, and predictable manneror measuring network performance. Being Layer-2 transport independent, IP SLAs can be configured end-to- end over disparate networks to best reflect the metrics that an end-user is likely to experience. Reference: https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/ipsla/configuration/15-mt/sla-15- mt-book/ sla_overview.html

Correct Answer: