DevNet Associate (Version 1.0) – DevNet Associate (200-901) Certification Practice Exam Answers

DevNet Associate (Version 1.0) – DevNet Associate (200-901) Certification Practice Exam Answers Full 100% 2024

1. Which two statements accurately describe an advantage or a disadvantage when deploying NAT for IPv4 in a network? (Choose two.)

   • NAT improves packet handling.
   • NAT adds authentication capability to IPv4.
   • NAT will impact negatively on switch performance.
   • NAT causes routing tables to include more information.
   • NAT provides a solution to slow down the IPv4 address depletion.
   • NAT introduces problems for some applications that require end-to-end connectivity.
     

     Explanation & Hint: Network Address Translation (NAT) is a technology that is implemented within IPv4 networks. One application of NAT is to use private IP addresses inside a network and use NAT to share a few public IP addresses for many internal hosts. In this way it provides a solution to slow down the IPv4 address depletion. However, since NAT hides the actual IP addresses that are used by end devices, it may cause problems for some applications that require end-to-end connectivity.

2. For what purpose are IPv4 addresses utilized?

   • An IPv4 address is used to uniquely identify a device on an IP network.
   • An IPv4 address is burned into the network card to uniquely identify a device.
   • An IPv4 address is used to uniquely identify the application that requested the information from a remote device.
   • An IPv4 address is used to identify the number of IP networks available.​
     

     Explanation & Hint: A MAC address is burned into a NIC to uniquely identify a device. A port number is used to uniquely identify the application that requested information. The subnet mask identifies how many hosts can be on a network and the network number. There is not really any parameter that identifies the number of free IP networks.

3. What is the purpose of a default gateway?

   • to physically connect a computer to a network
   • to provide a permanent address to a computer
   • to identify the network to which a computer is connected
   • to identify the logical address of a networked computer and uniquely identify it to the rest of the network
   • to identify the device that allows local network computers to communicate with devices on other networks
     

     Explanation & Hint: When a host needs to send a data packet to a destination host in another network, it cannot send it directly but rather the transmission will be routed. The sending host first decides if the destination host is on the same network. If not, it will send it to the default gateway. A default gateway is typically referred to the interface of a router that is attached to the local network.

4. What is one function of a Layer 2 switch?

   • forwards data based on logical addressing
   • duplicates the electrical signal of each frame to every port
   • learns the port assigned to a host by examining the destination MAC address
   • determines which interface is used to forward a frame based on the destination MAC address
     

     Explanation & Hint: A switch builds a MAC address table of MAC addresses and associated port numbers by examining the source MAC address found in inbound frames. To forward a frame onward, the switch examines the destination MAC address, looks in the MAC address for a port number associated with that destination MAC address, and sends it to the specific port. If the destination MAC address is not in the table, the switch forwards the frame out all ports except the inbound port that originated the frame.

5. What is the purpose of the subnet mask in conjunction with an IP address?

   • to uniquely identify a host on a network
   • to identify whether the address is public or private
   • to determine the subnet to which the host belongs
   • to mask the IP address to outsiders
     

     Explanation & Hint: With the IPv4 address, a subnet mask is also necessary. A subnet mask is a special type of IPv4 address that coupled with the IP address determines the subnet of which the device is a member. ​

6. What are two symptoms that DNS is an issue when developing and testing network scripts? (Choose two.)

   • 1XX status code
   • 403 error code
   • authentication failure
   • host IP address showing 169.x.x.x
   • no connection between the app and a remote server
     

     Explanation & Hint: Name resolution issues often manifest as lost network connectivity and authentication failures between a network app and a remote server. Common problems include defining the correct DNS server, a missing or incorrect DNS entry, an incorrect hostname, or a configuration issue on the DNS server being used.

7. A network app developer has configured an app to use a particular DNS server in order to test the application against a test database. The developer suspects a DNS issue. Which command could be used to verify a particular domain name?

   • nslookup
   • ssh -p 53
   • sudo puppet agent -t
   • ifconfig
     

     Explanation & Hint: The nslookup command is used to obtain an IP address for a specific domain name by querying a DNS server. The desired domain name follows the command and optionally the IP address of a particular DNS server.

8. A developer is using Cisco AnyConnect to connect through a VPN to the DevNet Sandbox. Which AnyConnect preference would cause the connection to fail?

   • Block Untrusted Connections
   • Certificate Store Override
   • Local Lan Access
   • Use Start Before Login
     

     Explanation & Hint: If the connection fails when using Cisco AnyConnect to connect to the DevNet Sandbox, check login credentials for any typing errors, the VPN URL of the DevNet Sandbox, and clear the Block Untrusted Connections option in the AnyConnect preferences.

9. A developer in a company receives feedback that an app is experiencing poor responses from an application on a server. The network engineer is looking for a solution that scales to multiple servers. Which technology should the engineer consider?

   • Docker
   • forward proxy
   • load balancer
   • server virtualization
     

     Explanation & Hint: Load balancing distributes server requests across multiple servers. The load balancer selects which server receives the client request and provides connectivity to device redundancy, high availability, and scalability.

10. Refer to the exhibit. A company uses three servers to support a new network app. The network administrator is looking to include a load balancer as part of the network design to improve the performance of the application response. Where should the load balancer be installed?

    

    • attached to the same switch as the servers
    • between the servers and storage
    • between the host and the cloud
    • within the cloud
      

      Explanation & Hint: Because server load balancing distributes server requests across multiple servers, the load balancer should be attached to the same switch that the servers are on.

11. Match the default port number to the network protocol. (Not all options are used.)

    

    Explanation & Hint:

12. Which two port numbers are commonly used for Telnet? (Choose two.)

    • 22
    • 23
    • 53
    • 830
    • 992
    • 8008
      

      Explanation & Hint: Telnet commonly uses 23 or 992 whereas the secure protocol SSH uses port 22. DNS uses port 53. HTTP uses port 80 and HTTPS uses 443. NETCONF uses port 830. RESTCONF can use ports 8008, 8080, or 8888.

13. What are two reasons a VLAN would be used on a Layer 2 switch? (Choose two.)

    • to allow a router to broadcast traffic between two networks
    • to allow traffic to be sent between two networks
    • to filter network traffic based on protocol port numbers
    • to create separate broadcast domains on a switch
    • to allow multiple networks to be created at Layer 2
      

      Explanation & Hint: A virtual local-area network (VLAN) is a separate Layer 2 network that has its own broadcast domain. A Layer 3 device such as a router or multilayer switch is required to communicate between VLANs.

14. What are two functions of MAC addresses in a LAN? (Choose two.)

    • to allow the transfer of frames from source to destination
    • to determine which host has priority to transfer data
    • to indicate the best path between separate networks
    • to associate with a specific network IP address
    • to uniquely identify a node on a network
      

      Explanation & Hint: All Ethernet network devices have a unique Media Access Control (MAC) address that is burned into the network interface card (NIC). The MAC address is used to direct data from a particular device to a specific network destination.

15. Match the protocol to the description. (Not all options are used.)

    

    Explanation & Hint:

16. In which situation would a router be used?

    • when authenticating to a REST API service on the local host
    • when performing a formal code review
    • when testing an app on a cloud-based server
    • when developing an app on a private server located on the same network as the development team
      

      Explanation & Hint: Cloud-based devices are on a remote network and a router is needed to send traffic from the developer (or the source network) toward a destination network (the network on which the server resides).

17. A user makes some REST API calls to a server and the responses from the server include third-party executable code. The user notices that the responses do not work. Which network device may prevent the third-party code from execution?

    • firewall
    • Layer 3 switch
    • proxy server
    • reverse proxy server
      

      Explanation & Hint: Firewalls and other policy-management tools may make third-party code execution (such as JavaScript or links to such code) impossible to use.