Cisco 100-490 Practice Test Questions, Exam Dumps

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100-490 Cisco Practice Test Questions and Exam Dumps

Question No 1:

Which protocol does TFTP typically use for transport?

A. RSVP
B. TCP
C. HTTP
D. UDP

Answer: D

Explanation:

TFTP (Trivial File Transfer Protocol) is a simplified version of FTP used primarily for transferring small files, such as configuration files or firmware updates, over a network. TFTP is known for its simplicity and low overhead, which makes it ideal for devices that have limited processing power or need a quick file transfer method.

Here’s a breakdown of the transport protocols and why D. UDP is the correct answer:

A. RSVP: RSVP (Resource Reservation Protocol) is a network control protocol designed to reserve resources across a network. It is used for quality of service (QoS) and is not associated with file transfer protocols like TFTP. RSVP is not used by TFTP.
B. TCP: TCP (Transmission Control Protocol) is a connection-oriented protocol that ensures reliable delivery of data by managing packet order, retransmissions, and error correction. While FTP typically uses TCP, TFTP does not. TFTP uses a simpler protocol, which does not require the connection establishment or the reliability features that TCP offers.
C. HTTP: HTTP (HyperText Transfer Protocol) is used for transferring hypertext (web pages) over the Internet. It is not used by TFTP, which is focused on simpler file transfers. HTTP also operates over TCP, but again, TFTP is not associated with it.
D. UDP: UDP (User Datagram Protocol) is a connectionless, lightweight protocol that does not guarantee delivery or order of packets. This makes it ideal for TFTP, where simplicity and low overhead are priorities. TFTP uses UDP on port 69 for file transfers, which allows it to operate efficiently in environments where reliability is less critical or can be handled at the application layer.

In conclusion, D. UDP is the correct answer, as TFTP typically uses UDP for transport due to its simplicity and low overhead, which is ideal for the basic file transfer needs of devices.

Question No 2:

What is the correct IPv6 address notation?

A. 2001:0DB8::/128
B. 2001:0DB8:0::
C. 2001:0DB8::1:1:1:1:1
D. 2001:0DB8:130F:0000:0000:7000:0000:140B

Correct Answer: D

Explanation:

IPv6 addresses are written in hexadecimal notation, separated by colons. They can also be abbreviated to make them easier to read. However, there are specific rules for what constitutes a valid IPv6 address. Let’s examine each option to determine which one follows the correct IPv6 address notation:

A. 2001:0DB8::/128: This address includes a CIDR (Classless Inter-Domain Routing) notation with a subnet mask ("/128"). While the address itself is correct, the addition of the "/128" implies a specific range or a specific single address, which isn't the usual form for expressing just an individual IPv6 address. Therefore, while it’s a valid notation for a network prefix, this isn’t the typical representation of an IPv6 address by itself.
B. 2001:0DB8:0::: This address is almost correct, but it includes unnecessary zeroes. In IPv6 notation, leading zeroes in any of the blocks can be omitted. The correct form would be 2001:0DB8::, which omits the zero block entirely. Thus, B is technically valid but unnecessarily verbose.
C. 2001:0DB8::1:1:1:1:1: This address is an example of IPv6 shorthand notation. While it might appear correct at first glance, it has a minor issue: the address has been compressed too much. According to IPv6 rules, it’s necessary to have exactly eight 16-bit blocks, and this address has only seven blocks (with the shorthand "::" reducing two blocks to zero). Thus, this address is not properly expanded to reflect the full format.
D. 2001:0DB8:130F:0000:0000:7000:0000:140B: This address is the correct expanded IPv6 address. It uses eight 16-bit hexadecimal blocks, as required by the IPv6 format. It does not contain unnecessary zero compression (though leading zeroes are included for clarity, which is perfectly valid in IPv6 notation). This is a properly formatted IPv6 address.

In conclusion, D is the correct IPv6 address notation because it fully adheres to the rules for formatting IPv6 addresses.

Question No 3:

Which two statements about Telnet and SSH are true? (Choose two.)

A. SSH is a protocol that provides a secure remote access connection to network devices.
B. SSH uses the well-known TCP port 23 for its communication.
C. A Telnet network management connection is dropped when a router reboots.
D. Telnet is a protocol that provides a secure remote access connection to network devices.
E. Telnet is preferred over SSH for security reasons.

Answer: A and C

Explanation:

Let's analyze each statement to determine which ones are correct:

Option A: SSH is a protocol that provides a secure remote access connection to network devices. – This statement is true. SSH (Secure Shell) is designed to provide a secure way to access and manage network devices and systems remotely. It encrypts all the traffic between the client and the server, which helps protect data integrity and confidentiality, making it far more secure than older protocols like Telnet.
Option B: SSH uses the well-known TCP port 23 for its communication. – This statement is incorrect. While Telnet uses TCP port 23 for communication, SSH uses TCP port 22. SSH is specifically designed to be a more secure alternative to Telnet, and it uses a different port to distinguish it from Telnet.
Option C: A Telnet network management connection is dropped when a router reboots. – This statement is true. If a network device like a router is rebooted, the Telnet connection is terminated, because the network session is interrupted during the reboot process. This happens because Telnet is not persistent across device restarts and does not maintain state information.
Option D: Telnet is a protocol that provides a secure remote access connection to network devices. – This statement is incorrect. Telnet is an older remote access protocol that does not provide security. Telnet transmits all data, including passwords, in plaintext, making it vulnerable to interception and eavesdropping. This is why SSH is preferred over Telnet in modern networks.
Option E: Telnet is preferred over SSH for security reasons. – This statement is incorrect. SSH is preferred over Telnet for security reasons, because SSH encrypts the data transmitted over the network, while Telnet does not. SSH ensures that sensitive information such as passwords and configuration data are not exposed to potential attackers.

In conclusion, the two true statements are A and C. SSH provides secure remote access, and Telnet connections are dropped when a router reboots.

Question No 4:

Which address facilitates the routing of packets over an IP network?

A. physical
B. transport
C. network
D. MAC

Correct answer: C

Explanation:

To understand which address facilitates the routing of packets over an IP network, it's important to recognize the role each type of address plays within the OSI (Open Systems Interconnection) model and the IP networking stack.

Why C is correct:

C. Network address
In an IP network, the network address is used to route packets from one device to another across networks. This typically refers to the IP address, which exists at Layer 3 (the Network Layer) of the OSI model. The IP address identifies a device on the network and helps route packets between different networks, making it the crucial address for routing in an IP-based network.

The IP address is used by routers to determine the best path for forwarding packets across the network, allowing them to travel from the source to the destination, potentially across multiple intermediate networks.

Why the other options are incorrect:

A. Physical address
A physical address, also known as a hardware address, refers to the MAC (Media Access Control) address. This address is used at the Data Link Layer (Layer 2) of the OSI model. The MAC address helps identify devices on the same local network segment but does not facilitate routing of packets across different networks. Routers use IP addresses (network addresses), not MAC addresses, for routing.
B. Transport address
A transport address refers to the port number used by protocols like TCP or UDP at the Transport Layer (Layer 4). While the transport address helps deliver data to the correct application process on a host, it does not play a role in the routing of packets between devices across networks. Routing decisions are made based on IP addresses (network addresses), not port numbers.
D. MAC address
A MAC address is a unique identifier assigned to network interfaces for communication on the local network (Data Link Layer). It is used for device identification within a local network and is not used for routing across networks. Routers operate using IP addresses to route packets to their destinations, not MAC addresses.

The address that facilitates the routing of packets over an IP network is the network address, typically represented by the IP address. This enables routers to determine the path of data across multiple networks, which is why the correct answer is C. Network.

Question No 5:

Which two IPv4 addresses can be assigned to a host computer? (Choose two.)

A. 255.255.255.255
B. 10.1.1.20
C. 0.0.0.0
D. 192.168.10.15
E. 292.10.3.4

Answer: B, D

Explanation:

In IPv4 addressing, certain addresses are reserved for specific purposes and cannot be assigned to a host computer. Let's go through the options and identify which addresses can be assigned to a host computer:

A. 255.255.255.255: This is a broadcast address. It is used for broadcasting messages to all hosts on the local network. It is not assignable to a single host as it’s meant for communication across all devices on the network. Therefore, this address cannot be assigned to a host.
B. 10.1.1.20: This is a valid private IPv4 address from the 10.0.0.0/8 network range. Private addresses are used within local networks and can be assigned to host computers. This address is valid and can be assigned to a host computer.
C. 0.0.0.0: This is a special address that is used to represent an unknown or unspecified address. It is typically used during network bootstrapping processes (e.g., when a device does not have an IP address). It cannot be assigned to a host computer as it does not represent a valid, usable address for hosts.
D. 192.168.10.15: This is a valid private IPv4 address from the 192.168.0.0/16 network range. Like 10.x.x.x addresses, 192.168.x.x addresses are reserved for local network use. This address is valid and can be assigned to a host computer in a private network.
E. 292.10.3.4: This is not a valid IPv4 address because IPv4 addresses must have values in the range of 0 to 255 for each of the four octets. The first octet here is 292, which is out of the valid range (0-255), making this address invalid.

Thus, the valid IPv4 addresses that can be assigned to a host computer are B (10.1.1.20) and D (192.168.10.15).

Question No 6:

What are two components of a WAN connection? (Choose two.)

A. CSU/DSU
B. router
C. bridge
D. hub
E. switch

Correct answer: A, B

Explanation:

A Wide Area Network (WAN) is a telecommunications network that spans a large geographic area, connecting multiple local area networks (LANs). The two components that are crucial in the setup and operation of a WAN connection are typically related to data transmission and routing between distant networks. Let’s examine the relevant options:

A. CSU/DSU (Channel Service Unit/Data Service Unit): This is an essential component for WAN connections, particularly in older technologies like leased lines. The CSU/DSU connects the router to the WAN and manages the data conversion between digital signals used by the router and the line's framing and formatting required by the carrier service. It helps in establishing the communication link over a WAN.
B. Router: A router is another crucial component of a WAN connection. It routes data packets between networks and directs the traffic between different parts of the WAN. Routers typically serve as the point of connection between a local network (LAN) and a WAN, ensuring data is transferred efficiently to the correct destination across wide areas.

Now let’s discuss the other options:

C. Bridge: A bridge is used to connect two similar networks or segments of a network and operate at the Data Link Layer (Layer 2). While it is used to extend or segment LANs, it is not typically a core component in WAN connections. Bridges help with traffic management within a LAN rather than across a WAN.
D. Hub: A hub is a basic networking device that operates at Layer 1 of the OSI model (the Physical Layer) and is used to connect multiple devices in a local area network (LAN). It does not play a role in WAN connections, as it simply broadcasts data to all devices in a LAN.
E. Switch: A switch operates at Layer 2 (Data Link Layer) of the OSI model and is used for managing traffic within a local area network (LAN) by forwarding data to specific devices based on MAC addresses. Like hubs, switches are not typically used in WAN connections, as they are more focused on LANs.

In conclusion, CSU/DSU and router are the key components involved in a WAN connection. The CSU/DSU enables the physical connection to the WAN, and the router directs the data traffic between different networks. Therefore, the correct answers are A and B.

Question No 7:

Which device is a DTE device?

A. CSU/DSU
B. router
C. cable modem
D. DSL modem

Correct answer: B

Explanation:

A Data Terminal Equipment (DTE) device is typically responsible for originating or terminating a data transmission. The router is classified as a DTE device because it directly interfaces with the network, typically through a modem, and handles the transmission of data between networks or to local devices. DTE devices are often involved in the transmission or receipt of data over a network and are typically the endpoint in a communication setup.

In contrast, a CSU/DSU (A) is a Data Circuit-Terminating Equipment device that is used in conjunction with DTE devices, but it is not the endpoint of the transmission. It helps manage the physical layer connection and conditioning the signal for transmission.

A cable modem (C) and DSL modem (D) both function as modems, which connect to a network, but they do not handle the routing or termination of data traffic on the network itself, which is typically the role of a DTE device like a router. Therefore, the correct answer is B, the router, which directly terminates the data transmission from the network into the local system.

Question No 8:

Which layer of the OSI model defines how data is formatted for transmission and how access to the physical media is controlled?

A. presentation
B. data link
C. network
D. transport

Correct answer: B

Explanation:

In the OSI (Open Systems Interconnection) model, the layer responsible for defining how data is formatted for transmission and how access to the physical media is controlled is the data link layer. The data link layer is the second layer in the OSI model and serves as the protocol layer that handles communication between devices on the same network segment.

The data link layer is responsible for breaking down data into frames and providing the necessary formatting for transmission. It also ensures the correct placement of data on the physical medium, such as determining when a device can access and transmit data on the network. It controls how devices communicate with each other within a local area network (LAN) and defines the media access control (MAC) methods.

The presentation layer (option A) is responsible for data translation and encryption, not for controlling access to physical media. It ensures that data is presented in a format that can be understood by the receiving application layer.

The network layer (option C) is responsible for routing data between different networks and managing the addressing scheme, such as IP addresses. This layer is concerned with how data travels across multiple networks but does not manage access to the physical medium.

The transport layer (option D) ensures the reliable transfer of data between end-to-end devices, handling flow control, error correction, and retransmission. However, it does not define how data is formatted or how the media is accessed.

Thus, the data link layer is the layer that governs data formatting and media access control, making option B the correct answer.

Question No 9:

Which command shows the status of power supplies and sensor temperatures?

A. show hardware
B. show module
C. show environment
D. show diag

Correct answer: C

Explanation:

The correct command for viewing the status of power supplies and sensor temperatures is show environment. This command provides detailed information about the environmental status of the system, including power supply health, fan status, temperature readings, and other key factors that help monitor the operational conditions of the hardware.

Let’s break down the other options:

A. show hardware: This command is used to display a list of hardware components in the system, but it typically does not provide detailed information about environmental conditions such as temperatures or power supplies.
B. show module: This command displays the status of specific hardware modules, but it does not focus on environmental conditions like power supply or temperature monitoring.
D. show diag: This command shows diagnostic information related to the hardware and can sometimes provide insights into specific hardware errors, but it is not primarily used to display environmental data like sensor temperatures or power supply status.

Therefore, the show environment command is the most accurate choice for checking the status of power supplies and sensor temperatures.

Question No 10:

What are two standard fiber-optic connectors? (Choose two.)

A. Lucent
B. rollover
C. subscriber
D. multidimension
E. crossover

Correct answer: A & C

Explanation:

Fiber-optic connectors are used to connect fiber-optic cables to other devices or systems. Two standard fiber-optic connectors commonly used are Lucent and Subscriber. Lucent connectors are often referred to as LC connectors and are known for their small form factor, making them ideal for high-density applications. Subscriber connectors, commonly referred to as SC connectors, are widely used in networking applications for their durability and ease of use. These connectors are designed for precision and high performance in connecting fiber-optic systems.

The other options—rollover, multidimension, and crossover—are not recognized as standard fiber-optic connectors. "Rollover" refers to a type of cable used for console connections, "multidimension" is not a standard term related to fiber-optic technology, and "crossover" typically refers to cables used for networking, such as Ethernet cables, but not fiber-optic connectors.