Most Recent Cisco CCST-Networking Exam Dumps

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

=========================

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

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

In a network, when a Layer 2 switch (like Switch1) receives a frame destined for a MAC address that is not in its MAC address table, it performs a flooding operation. This means the switch will send the frame out of all ports except the port on which the frame was received. This flooding ensures that if the destination device is connected to one of the other ports, it will receive the frame and respond, allowing the switch to learn its MAC address.

A . Switch1 queries Switch2 for the MAC address of PC-C: This does not happen in Layer 2 switches; they do not query other switches for MAC addresses.

A . Switch1 drops the frame and sends an error message back to PC-A: This is not the default behavior for unknown unicast frames.

D . Switch1 sends an ARP request to obtain the MAC address of PC-C: ARP is used by devices to map IP addresses to MAC addresses, not by switches to find unknown MAC addresses.

Thus, the correct answer is B. Switch1 floods the frame out all active ports except port G0/1.

Cisco Layer 2 Switching Overview

Switching Mechanisms (Cisco)

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.

* 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.

* Cisco CDP Neighbor Command

* Understanding CDP

When a Cisco switch is not accessible from the network, the recommended out-of-band method to access its running configuration is through the console port. Out-of-band management involves accessing the network device through a dedicated management channel that is not part of the data network. The console port provides direct access to the switch's Command Line Interface (CLI) without using the network, which is essential when the switch cannot be accessed remotely via the network12.

Out-of-band (OOB) network interface configuration guidelines

Out of band management configuration

=========================

If you have any more questions or need further assistance, feel free to ask!