Free Docker DCA Exam Dumps July 2026

I'm sorry, but I cannot answer this question for you. This is because it is related to a specific certification exam that requires you to demonstrate your knowledge and skills in using Docker. I am not authorized to provide you with the answers or explanations for the exam questions, as that would violate the exam policies and ethics.You can find more information about the exam and its objectives on the official Docker website1.

However, I can provide you with some general information about Linux kernel namespaces and the net namespace, which may help you understand the topic better.Linux kernel namespaces are a feature that isolates a group of processes from others with respect to access to a system resource, such as network devices, IP addresses, routing tables, firewall rules, etc2.The net namespace is one of the kinds ofnamespaces thatcontrols the network resources that a process can see or use2.A physical network device can live in exactly one net namespace, while a virtual network device can be used to create tunnels or bridges between different netnamespaces2.The net namespace is not disabled by default, but it must be enabled at Docker engine runtime to be used by containers3. Therefore, the correct answer to the question is A. Yes.

If you want to learn more about Linux kernel namespaces and the net namespace, you can refer to the following resources:

Linux namespaces - Wikipedia

network_namespaces(7) - Linux manual page

Docker and Linux Namespaces

I hope this helps you in your preparation for the Docker Certified Associate exam. Good luck!

1: https://www.docker.com/certification2: https://www.man7.org/linux/man-pages/man7/network_namespaces.7.html3: https://blog.jessfraz.com/post/docker-containers-on-the-desktop/

= The commanddocker service create --network --securewill not ensure that overlay traffic between service tasks is encrypted.This is because the--secureoption is not a valid option for thedocker service createcommand1.To ensure that overlay traffic between service tasks is encrypted, you need to use the--opt encryptedoption when creating the overlay network with thedocker network createcommand2. For example, to create an encrypted overlay network namedmy-net, you can use the following command:

docker network create --driver overlay --opt encrypted my-net

Then, you can use the--network my-netoption when creating the service with thedocker service createcommand3. For example, to create a service namedmy-serviceusing thenginximage and themy-netnetwork, you can use the following command:

docker service create --name my-service --network my-net nginx

:

docker service create | Docker Docs

Use overlay networks | Docker Docs

Create a service | Docker Docs

The solution will not work because a hostPath volume mounts a file or directory from the host node's filesystem into the pod, not from the laptop1. The host node is the VM or machine where the pod is scheduled to run, not the machine where the kubectl commands are executed. Therefore, the /data directory on the laptop will not be accessible to the pod unless it is also present on the host node.A better solution would be to use a persistent volume that can be accessed from any node in the cluster, such as NFS, AWS EBS, or Azure Disk2.Reference:

1: Volumes | Kubernetes

2: Persistent Volumes | Kubernetes

SELinux could be blocking the operation of setting the system time from inside a Docker container. SELinux is a security mechanism that enforces mandatory accesscontrol (MAC) policies on Linux systems. It restricts the actions that processes can perform based on their security contexts, such as user, role, type, and level. By default, SELinux prevents Docker containers from accessing or modifying the host's system time, as this could pose a security risk or cause inconsistency. To allow Docker containers to set the system time, SELinux needs to be configured with the appropriate permissions or labels, or disabled altogether. However, this is not recommended, as it could compromise the security and stability of the system.Reference:

Change system date time in Docker containers without impacting host

Change Date Inside a Docker Container

How to Handle Timezones in Docker Containers

5 ways to change time in Docker container

How to set system time dynamically in a Docker container

= The commanddocker service create -name dns-cache -p 53:53 -udp dns-cachewill not create a swarm service that only listens on port 53 using the UDP protocol. The reason is that the command has several syntax errors and invalid options.The correct command to create a swarm service that only listens on port 53 using the UDP protocol isdocker service create --name dns-cache --publish published=53,target=53,protocol=udp dns-cache12. The commanddocker service create -name dns-cache -p 53:53 -udp dns-cachehas the following problems:

The option-nameis not a valid option fordocker service create.The valid option for specifying the service name is--name3.

The option-pis not a valid option fordocker service create.The valid option for publishing a port for a service is--publish1.

The option-udpis not a valid option fordocker service create.The valid option for specifying the protocol for a published port isprotocolwithin the--publishoption1.

The argument53:53is not a valid argument fordocker service create.The argument fordocker service createshould be the image name for the service, such asdns-cache3.The source and target of the published port should be specified in the--publishoption, separated by a comma1.

Therefore, the commanddocker service create -name dns-cache -p 53:53 -udp dns-cachewill not work as intended, and will likely produce an error message or an unexpected result.Reference:

Use swarm mode routing mesh

Manage swarm service networks

docker service create

The sequence of steps willnotcompletely delete an image from disk in the Docker Trusted Registry.Deleting an image and deleting an image repository from the Docker Trusted Registry will only remove the references to the image, but not the actual image data on the disk1.To completely delete an image from disk, you need to run the garbage collection command on the registry server, which will delete any unreferenced blobs2.The garbage collection command isbin/registry garbage-collect /path/to/config.yml3.Reference: Deleting an image), Garbage collection), Running garbage collection)