Important Cisco 100-150 Exam Questions

Answer: A, D

Explanation:

The private IP address ranges that are set aside specifically for use within private networks and not routable on the internet are as follows:

Class A: 10.0.0.0 to 10.255.255.255

Class B: 172.16.0.0 to 172.31.255.255

Class C: 192.168.0.0 to 192.168.255.255

These ranges are defined by the Internet Assigned Numbers Authority (IANA) and are used for local communications within a private network123.

Given the options: A. 172.16.0.0 to 172.31.255.255 falls within the Class B private range. B. 192.16.0.0 to 192.16.255.255 is not a recognized private IP range. C. 11.0.0.0 to 11.255.255.255 is not a recognized private IP range. D. 192.168.0.0 to 192.168.255.255 falls within the Class C private range.

Therefore, the correct selections that the company should use for their private networks are A and D.

Reserved IP addresses on Wikipedia

Private IP Addresses in Networking - GeeksforGeeks

Understanding Private IP Ranges, Uses, Benefits, and Warnings

Answer: A, C

Explanation:

Statement A: 'A detailed description of the fault.' This is essential for support staff to understand the nature of the problem and begin troubleshooting effectively.

Statement C: 'A description of the conditions when the fault occurs.' This helps in reproducing the issue and identifying patterns that might indicate the cause of the fault.

Statement B: 'Details about the computers connected to the network.' While useful, this is not as immediately critical as understanding the fault itself and the conditions under which it occurs.

Statement D: 'The actions taken to resolve the fault.' This is important but typically follows the initial report.

Statement E: 'The description of the top-down fault-finding procedure.' This is more of a troubleshooting methodology than information typically included in an initial support ticket.

Best Practices for Submitting Support Tickets: Support Ticket Guidelines

Answer: C

Explanation:

The header of a UDP (User Datagram Protocol) segment includes port numbers. Specifically, it contains the source port number and the destination port number, which are used to identify the sending and receiving applications. UDP headers do not include IP addresses or MAC addresses, as those are part of the IP and Ethernet frame headers, respectively. Additionally, UDP does not use sequence numbers, which are a feature of TCP (Transmission Control Protocol) for ensuring reliable delivery of data segments1.

Segmentation Explained with TCP and UDP Header

User Datagram Protocol (UDP) - GeeksforGeeks

Which three fields are used in a UDP segment header

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UDP Header: The header of a UDP segment includes the following key fields:

Source Port: The port number of the sending application.

Destination Port: The port number of the receiving application.

Length: The length of the UDP header and data.

Checksum: Used for error-checking the header and data.

IP Addresses: These are included in the IP header, not the UDP header.

Sequence Numbers: These are part of the TCP header, not UDP.

MAC Addresses: These are part of the Ethernet frame header and are not included in the UDP header.

RFC 768 - User Datagram Protocol: RFC 768

Cisco Guide on UDP: Cisco UDP Guide

Answer: A, C

Explanation:

* Statement A: 'The trace successfully reached the www.cisco.com server.' This is true as indicated by the 'Trace complete' message at the end, showing that the trace has reached its destination.

* Statement C: 'The IPv6 address associated with the www.cisco.com server is 2600:1408:c400:38d::b33.' This is true because the final hop in the trace, which is the destination, has this IPv6 address.

* Statement B: 'The trace failed after the fourth hop.' This is incorrect as the trace continues beyond the fourth hop, despite some intermediate timeouts.

* Statement D: 'The routers at hops 5 and 6 are offline.' This is not necessarily true. The routers might be configured to not respond to traceroute requests.

* Statement E: 'The device sending the trace has IPv6 address 2600:1408:c400:38d::b33.' This is incorrect; this address belongs to the destination server, not the sender.

* Understanding Traceroute: Traceroute Guide

Answer: C

Explanation:

On a Cisco switch, a port with a blinking green LED typically indicates that the port is up (active) and is currently transmitting or receiving data. This is a normal state indicating active traffic on the port.

* A. Link is up with cable malfunctions: Usually indicated by an amber or blinking amber light.

* B. Link is up and not stable: Not typically indicated by a green blinking light.

* D. Link is up and there is no activity: Would be indicated by a solid green light without blinking.

Thus, the correct answer is C. Link is up and active.

* Cisco Switch LED Indicators

* Cisco Ethernet Switch LED Patterns