What is the most compressed valid format of the IPv6 address 2001:0db8:0000:0016:0000:001b: 2000:0056?
Correct Answer:
D
IPv6 addresses can be compressed by removing leading zeros and replacing consecutive groups of zeros with a double colon (::). Here??s how to compress the address 2001:0db8:0000:0016:0000:001b:2000:0056:
✑ Remove leading zeros from each segment:
✑ Replace the longest sequence of consecutive zeros with a double colon (::). In this case, the two consecutive zeros between the 16 and 1b:
Thus, the most compressed valid format of the IPv6 address is 2001:db8:0:16::1b:2000:56.
References:=
✑ Cisco Learning Network
✑ IPv6 Addressing (Cisco)
Which command will display the following output?
Correct Answer:
B
The command that will display the output provided, which includes capability codes, local interface details, device IDs, hold times, and platform port ID capabilities, is the show cdp neighbor command. This command is used in Cisco devices to display current information about neighboring devices detected by Cisco Discovery Protocol (CDP), which includes details such as the interface through which the neighbor is connected, the type of device, and the port ID of the device1.
References :=
•Cisco - show cdp neighbors
The provided output is from the Cisco Discovery Protocol (CDP) neighbor table. The show cdp neighbor command displays information about directly connected Cisco devices, including Device ID, Local Interface, Holdtime, Capability, Platform, and Port ID.
•A. show mac-address-table: Displays the MAC address table on the switch.
•C. show inventory: Displays information about the hardware inventory of the device.
•D. show ip interface: Displays IP interface status and configuration. Thus, the correct answer is B. show cdp neighbor.
References :=
•Cisco CDP Neighbor Command
•Understanding CDP
Which information is included in the header of a UDP segment?
Correct Answer:
C
The header of a UDP (User Datagram Protocol) segment includesport 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.
References:=
✑ Segmentation Explained with TCP and UDP Header
✑ User Datagram Protocol (UDP) - GeeksforGeeks
✑ Which three fields are used in a UDP segment header
=========================
✑ UDP Header: The header of a UDP segment includes the following key fields:
✑ 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.
References:
✑ RFC 768 - User Datagram Protocol: RFC 768
✑ Cisco Guide on UDP: Cisco UDP Guide
A user reports that a company website is not available. The help desk technician issues a tracert command to determine if the server hosting the website isreachable over the network. The output of the command is shown as follows:
What can you tell from the command output?
Correct Answer:
C
The tracert command output shows the path taken to reach the destination IP address, 192.168.1.10. The command output indicates:
•Hops 1 and 2 are successfully reached.
•Hop 3 times out, meaning the router at hop 3 did not respond to the tracert request. However, this does not necessarily indicate a problem with forwarding packets, as some routers may be configured to block or not respond to ICMP requests.
•Hops 4 and 5 are successfully reached, with hop 5 being the destination IP 192.168.1.10, indicating that the server is reachable.
Thus, the correct answer is C. The server with the address 192.168.1.10 is reachable over the network.
References :=
•Cisco Traceroute Command
•Understanding Traceroute
The tracert command output indicates that the server with the address 192.168.1.10 is reachable over the network. The asterisk (*) at hop 3 suggests that the probe sent to that hop did not return a response, which could be due to a variety of reasons such as a firewall blocking ICMP packets or the router at that hop being configured not to respond to ICMP requests. However, since the subsequent hops (4 and 5) are showing response times, it means that the packets are indeed getting through and the server is reachable12. References :=
•How to Use Traceroute Command to Read Its Results
•How to Use the Tracert Command in Windows
A host is given the IP address 172.16.100.25 and the subnet mask 255.255.252.0. What is the CIDR notation for this address?
Correct Answer:
D
The CIDR (Classless Inter-Domain Routing) notation for the subnet mask 255.255.252.0 is /22. This notation indicates that the first 22 bits of the IP address are used for network identification, and the remaining bits are used for host addresses within the network1. References :=
•Subnet Cheat Sheet – 24 Subnet Mask, 30, 26, 27, 29, and other IP Address CIDR Network References
=========================
•Subnet Mask to CIDR Notation: The given subnet mask is 255.255.252.0. To convert this to CIDR notation:
•Convert the subnet mask to binary: 11111111.11111111.11111100.00000000
•Count the number of consecutive 1s in the binary form: There are 22 ones.
•Therefore, the CIDR notation is /22. References:
•Understanding Subnetting and CIDR: Cisco CIDR Guide
