Pass the Cisco CCST 100-150 Questions and answers with ExamsMirror

•Statement B: "The same default gateway IPv4 address is configured on each host on the local network." This is true because all hosts on the same local network (subnet) use the same default gateway IP address to send packets destined for other networks.

•Statement D: "The default gateway is the IPv4 address of the router interface connected to the same local network as the host." This is true because the default gateway is the IP address of the router's interface that is directly connected to the local network.

•Statement A: "The IPv4 address of the default gateway must be the first host address in the subnet." This is not necessarily true. The default gateway can be any address within the subnet range.

•Statement C: "The default gateway is the Loopback0 interface IPv4 address of the router connected to the same local network as the host." This is not true; the default gateway is the IP address of the router's physical or logical interface connected to the local network.

•Statement E: "Hosts learn the default gateway IPv4 address through router advertisement messages." This is generally true for IPv6 with Router Advertisement (RA) messages, but not typically how IPv4 hosts learn the default gateway address.

References:

•Cisco Default Gateway Configuration: Cisco Default Gateway

The IEEE 802.11 standard contains the specifications for Wi-Fi networks. It is a set of media access control (MAC) and physical layer (PHY) specifications for implementing wireless local area network (WLAN) computer communication in various frequencies, including but not limited to 2.4 GHz, 5 GHz, and 6 GHz1. This standard is maintained by the Institute of Electrical and Electronics Engineers (IEEE) and is commonly referred to as Wi-Fi. The standard has evolved over time to include several amendments that improve speed, range, and reliability of wireless networks.

References :=

•The Most Common Wi-Fi Standards and Types, Explained

•802.11 Standards Explained: 802.11ax, 802.11ac, 802.11b/g/n, 802.11a

•Wi-Fi Standards Explained - GeeksforGeeks

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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

Statement 1: Low bandwidth can increase network latency.

True: Low bandwidth can result in increased network latency because the network may become congested, leading to delays in data transmission.

Statement 2: High levels of network latency decrease network bandwidth.

False: High levels of network latency do not decrease the available network bandwidth, but they do affect the perceived performance and throughput of the network.

Statement 3: You can increase throughput by decreasing network latency.

True: Decreasing network latency can increase throughput because data can be transmitted more quickly and efficiently without delays.

Bandwidth vs. Latency: Bandwidth refers to the maximum rate at which data can be transferred over a network path. Latency is the time it takes for a data packet to travel from the source to the destination.

Low bandwidth can cause network congestion, which can increase latency as packets wait to be transmitted.

High latency does not reduce the actual bandwidth but can affect the overall performance and efficiency of data transmission.

Reducing latency can lead to higher throughput because the network can handle more data in a given period without delays.

References:

Network Performance Metrics: Cisco Network Performance

Understanding Bandwidth and Latency: Bandwidth vs. Latency

Understanding How Layer 2 Switches Handle Unknown MAC Addresses

Switches operate at Layer 2 (Data Link Layer) of the OSI model and maintain a MAC address table (CAM table) to forward frames efficiently.

When a switch receives a frame, it checks its MAC address table to see if it knows the destination MAC address.

If the destination MAC address is not in the table (meaning the switch does not know which port leads to PC-C), the switch follows the flooding behavior.

What Happens When Switch1 Receives a Frame from PC-A to PC-C?

Switch1 checks its MAC table:

The source MAC (PC-A) is recorded in the table on port G0/1.

The destination MAC (PC-C) is not in the table.

Switch1 does not know where PC-C is:

It floods the frame out of all active ports except the port it was received on (G0/1).

This means the frame is sent to:

Switch2 (via G0/23)

PC-B (via G0/2)

Switch2 receives the frame and follows the same process:

If Switch2 has PC-C's MAC in its table, it forwards the frame appropriately.

If not, it floods the frame again until PC-C replies.

Once PC-C responds, Switch1 and Switch2 learn its MAC address and update their tables.

Why Other Options Are Incorrect:

❌ A. Switch1 queries Switch2 for the MAC address of PC-C.

Incorrect: Switches do not query other switches directly for MAC addresses. Instead, they rely on learning MAC addresses dynamically through frame forwarding.

❌ B. Switch1 drops the frame and sends an error message back to PC-A.

Incorrect: Switches do not drop frames for unknown MAC addresses. Instead, they flood the frames out all ports except the incoming port.

❌ D. Switch1 sends an ARP request to obtain the MAC address of PC-C.

Incorrect:

ARP (Address Resolution Protocol) is only used to resolve IP addresses to MAC addresses.

Since PC-A is sending a frame (Layer 2), not an IP packet (Layer 3), ARP is not involved here.

Conclusion

Since Switch1 does not know the destination MAC address, it floods the frame out all active ports except the port it was received on. This is the default behavior of Layer 2 switches when they encounter an unknown MAC address.

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

References

Cisco CCNA 200-301 Official Guide – MAC Address Table & Frame Forwarding

RFC 894 – Standard for Ethernet Frame Forwarding

Cisco Networking Essentials – Switch Flooding Behavior

A firewall can direct all web traffic to a specific IP address.

True: Firewalls can be configured to perform Network Address Translation (NAT) and port forwarding, which can direct all web traffic (typically on port 80 and 443) to a specific internal IP address.

A firewall can block traffic to specific ports on internal computers.

True: Firewalls can be configured with access control lists (ACLs) or rules to block traffic to specific ports on internal computers, enhancing security by restricting unwanted or harmful traffic.

A firewall can prevent specific apps from running on a computer.

False: Firewalls typically control traffic flow and do not prevent specific applications from running on a computer. Application control is usually managed by endpoint security software or application control systems.

Directing Web Traffic: Firewalls can manage traffic redirection using NAT and port forwarding rules to route web traffic to designated servers or devices within the network.

Blocking Specific Ports: Firewalls can enforce security policies by blocking or allowing traffic based on port numbers, ensuring that only permitted traffic reaches internal systems.

Application Control: While firewalls manage network traffic, preventing applications from running typically requires software specifically designed for endpoint protection and application management.

References:

Understanding Firewalls: Firewall Capabilities

Network Security Best Practices: Network Security Guide

•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.

References:

•Understanding Traceroute: Traceroute Guide

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.

References :=

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.

References:

RFC 768 - User Datagram Protocol: RFC 768

Cisco Guide on UDP: Cisco UDP Guide

The two interfaces are administratively shut down:

False: The output does not show any "shutdown" command under the interfaces, which would indicate that they are administratively shut down. Therefore, they are likely in their default state, which is administratively up.

The two interfaces have default IP addresses assigned:

False: The output does not show any IP address configuration. In the default state, interfaces do not have IP addresses assigned unless explicitly configured.

The two interfaces can communicate over Layer 2:

True: By default, interfaces on a switch are Layer 2 interfaces capable of forwarding Ethernet frames. As there is no configuration provided that changes this, it can be assumed they can communicate over Layer 2.

Interface Status: The absence of the "shutdown" command means the interfaces are not administratively shut down.

IP Address Assignment: There is no evidence in the output that IP addresses have been assigned to the interfaces, which would typically be shown as "ip address" entries.

Layer 2 Communication: Switch interfaces in their default state operate at Layer 2, enabling them to forward Ethernet frames and participate in Layer 2 communication.

References:

Cisco IOS Interface Configuration: Cisco Interface Configuration

Understanding Cisco Switch Interfaces: Cisco Switch Interfaces

The tracert command is used to determine the route taken by packets across an IP network. When a user reports that an external web page is not loading, while other resources are accessible, it suggests there might be an issue at a certain point in the network path to the specific web page. The tracert command helps to diagnose where the breakdown occurs by displaying a list of routers that the packets pass through on their way to the destination. It can identify the network segment where the packets stop progressing, which is valuable for pinpointing where the connectivity issue lies. References := Cisco CCST Networking Certification FAQs – CISCONET Training Solutions, Command Prompt (CMD): 10 network-related commands you should know, Network Troubleshooting Commands Guide: Windows, Mac & Linux - Comparitech, How to Use the Traceroute and Ping Commands to Troubleshoot Network, Network Troubleshooting Techniques: Ping, Traceroute, PathPing.

•tracert Command: This command is used to determine the path packets take to reach a destination. It lists all the hops (routers) along the way and can help identify where the delay or failure occurs.

•ping -t: This command sends continuous ping requests and is useful for determining if a host is reachable but does not provide path information.

•ipconfig /all: This command displays all current TCP/IP network configuration values and can be used to verify network settings but not to trace a network path.

•nslookup: This command queries the DNS to obtain domain name or IP address mapping, useful for DNS issues but not for tracing network paths.

References:

•Microsoft tracert Command: tracert Command Guide

•Troubleshooting Network Issues with tracert: Network Troubleshooting Guide