Docker - Networking - multichoice questions

Given the below executed commands:

docker network create mynet5
docker run --name mynginx --network mynet5 nginx

Answer the below 3 questions.

Question 1

What is the networking driver used by the network mynginx is connected to?

• Overlay
• None
• Host
• Bridge

Question 2

You are told that the container's IP address is: 172.18.0.2. Choose the correct sentence(s).

The mynginx container:

• Is accessible form the host machine using http://localhost:80.
• Is accessible form the host machine using http://172.18.0.2:80.
• Is accessible form other containers attached to network mynet5 using http://172.18.0.2:80.
• Is accessible form other containers attached to network mynet5 using http://mynginx:80.
• The container is not accessible.

Question 3

The mynginx container was detached from mynet5 network and attached to the default bridge network. Choose the correct sentence(s).

The mynginx container:

• Is accessible form the host machine using http://localhost:80.
• Is accessible form the host machine using http://172.18.0.2:80.
• Is accessible form other containers attached to network mynet5 using http://172.18.0.2:80.
• Is accessible form other containers attached to network mynet5 using http://mynginx:80.
• The container is not accessible.

Question 4

What is the name of the network interface of the default bridge network which Docker is shipped with?

Hint: ip address

• lo
• docker0
• veth
• virbr0

Question 5

Given the following running container:

docker run -it busybox /bin/sh

DNS queries requested from within this container:

• Uses Docker's embedded DNS server.
• Uses the DNS servers configured on the host machine.
• Uses the bridge custom DNS server.
• None of the above.

Question 6

Containers can have multiple IP addresses:

• When connected to multiple networks
• Container can have only one IP address.
• When connected to an overlay networks .
• When running under the host network.

Question 7

In order to execute the following command successfully:

docker run -p 8080:80 my-app

• The docker daemon service should be up and running.
• Port 8080 must not be bound to another process in the host machine.
• Port 80 must not be bound to another process in the host machine.
• Port 8080 must not be bound to another process other running containers launched from the my-app image.
• Port 80 must not be bound to another process other running containers launched from the my-app image.

Given the following running container:

docker run --network host redis

Answer the below 4 questions

Question 8

Running the ip address command from within the container (you can install the command by apt update && apt install iproute2):

• Lists the network interfaces of the host machine.
• Lists the network interfaces used by docker daemon.
• Lists the virtual bridge network interface of the container.
• None of the above

Question 9

Choose the correct sentence(s):

• The container can be connected to user-defined bridge network.
• The container cannot be connected to user-defined bridge network.
• The container can be connected to the default bridge network.
• The container cannot be connected to the default bridge network.

Question 10

The user tries to run another redis container as follows:

docker run --network host redis

Why is the command failed?

• The container must have a name other than redis.
• Only one container can be run on the host network for each docker image.
• The network host doesn't exist in the host machine.
• Port 6379 is already in use by the first running redis.

Question 11

Assume port 6378 is bound to another process in the host machine, while port 6379 is free. What would happen if instead of running the original command, the user would have run:

docker run -p 6378:6379 --network host redis

• The container will fail since port 6378, which is published on the host machine, is already in use.
• The container will run since port 6379 is not bound to any process.
• The container will fail since port 6379, which is published on the host machine, is already in use.
• The container will run since port 6378 is not bound to any process.