DCA Communication & Stakeholder Relations 3

Question 1

A network engineer needs to understand how Docker assigns DNS names to services in a user-defined bridge network. What is the default behavior?

Accepted Answer

Containers are reachable by their name as DNS hostnames

Answer

User-defined bridge networks include an embedded DNS server that resolves container names to their IP addresses automatically.

Question 2

A stakeholder wants to limit which containers can communicate on a shared host. Which Docker feature best enforces network segmentation?

Accepted Answer

User-defined networks per team/application

Answer

User-defined networks isolate container communication so only containers on the same network can communicate by default.

Question 3

During a post-incident review, a stakeholder asks which Docker component routes traffic between services in a Swarm. What is the correct answer?

Accepted Answer

The ingress overlay network and routing mesh

Answer

Docker Swarm uses an ingress overlay network and routing mesh to distribute incoming traffic across service replicas.

Question 4

An SRE team wants to communicate resource constraints to developers. Which Docker flag limits a container's CPU usage?

Accepted Answer

--cpus

Answer

The `--cpus` flag specifies the number of CPUs available to the container as a decimal value.

Question 5

A compliance officer asks how to audit which images are running in production Docker environments. What is the best approach?

Accepted Answer

Use `docker ps --no-trunc` to list containers with full image digests

Answer

`docker ps --no-trunc` shows full image IDs and names for all running containers, enabling audit of active images.

DCA - Docker Certified Associate Exam Practice Test