Container networking in Microservices - Practice Problems & Coding Challenges

Challenge - 5 Problems

🧠 Conceptual

intermediate

Understanding Container Network Isolation

Which option best describes how container network isolation is typically achieved in Docker?

A Each container gets its own network namespace, isolating its network stack from others.

B Containers share the host's network stack without any isolation.

C Containers use a shared IP address but different ports without network namespaces.

D Containers communicate only through shared volumes, not networks.

💡 Hint

Think about how containers keep their network traffic separate.

Docker uses network namespaces to give each container its own isolated network stack, including interfaces and IP addresses.

❓ Architecture

intermediate

Choosing a Container Network Model

You need to design a microservices system where containers on different hosts must communicate securely and efficiently. Which container network model is best suited?

A Host network model, where containers share the host's network stack.

B Bridge network model, where containers communicate only on the same host.

C Overlay network model, which allows containers across hosts to communicate securely.

D None, containers cannot communicate across hosts.

💡 Hint

Consider multi-host communication with security.

Overlay networks create a virtual network that spans multiple hosts, enabling secure container communication across hosts.

❓ scaling

advanced

Scaling Container Networking for High Traffic

Your containerized application experiences high traffic and you want to scale networking without bottlenecks. Which approach best supports scalable container networking?

A Use a single bridge network for all containers to simplify routing.

B Assign static IPs to containers and manually configure routing tables.

C Disable container networking and use host networking for all containers.

D Implement a distributed service mesh to manage container communication and load balancing.

💡 Hint

Think about dynamic routing and load balancing at scale.

Service meshes provide dynamic routing, load balancing, and observability, which help scale container networking efficiently.

❓ tradeoff

advanced

Tradeoffs Between Host and Overlay Networking

What is a key tradeoff when choosing host networking over overlay networking for containers?

A Host networking provides better performance but less network isolation compared to overlay.

B Overlay networking has no encryption, while host networking encrypts all traffic.

C Host networking offers better isolation but worse performance than overlay.

D Overlay networking requires containers to share the host's IP address.

💡 Hint

Consider isolation versus performance.

Host networking shares the host's network stack, improving performance but reducing isolation, while overlay networks isolate containers but add overhead.

❓ estimation

expert

Estimating Network Capacity for Containerized Microservices

You run 1000 containers, each sending 1 Mbps traffic continuously. What is the minimum network bandwidth your container host cluster must support to avoid bottlenecks?

A 100 Gbps

B 10 Gbps

C 100 Mbps

D 1 Gbps

💡 Hint

Multiply containers by their traffic and convert units.

1000 containers × 1 Mbps = 1000 Mbps = 1 Gbps minimum; considering overhead and peak, 10 Gbps is safer.