KCSA Kubernetes Threat Model Practice Question
An attacker compromises a cluster node and attempts to inspect container communication. By default, how is pod-to-pod network traffic handled across different nodes in a standard Kubernetes cluster without a service mesh or CNI encryption enabled?
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Transmitted in plain text across the network fabric, making it vulnerable to sniffing
Standard Kubernetes CNI plugins transmit pod-to-pod traffic in plain text across the underlying network fabric unless an encrypted overlay network (like IPsec or WireGuard) or a service mesh providing mTLS is configured.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Encrypted automatically using mandatory 256-bit AES transport layer security
Why it's wrong here
Kubernetes does not enforce automatic transport encryption between pods out-of-the-box.
- ✗
Blocked entirely by default unless a LoadBalancer service is declared
Why it's wrong here
Pods can communicate freely across the cluster flat network unless restricted by NetworkPolicies.
- ✗
Routed exclusively through the etcd secure TLS database tunnel
Why it's wrong here
Pod data traffic never flows through the etcd database.
- ✓
Transmitted in plain text across the network fabric, making it vulnerable to sniffing
Why this is correct
Default CNI configurations do not encrypt node-to-node or pod-to-pod transit traffic, allowing packet capture on intermediate networks.
Quick reference
VPN Protocol Comparison
| Protocol | Port | Encryption | Authentication | Use Case |
|---|---|---|---|---|
| IKEv2 / IPsec | UDP 500 / 4500 | AES-256 | Certificates / PSK | Site-to-site & remote access |
| SSL / TLS VPN | TCP 443 | TLS 1.3 | Certificates / MFA | Clientless remote access |
| L2TP / IPsec | UDP 1701 | AES (IPsec) | PSK / Certificates | Legacy remote access |
| WireGuard | UDP 51820 | ChaCha20 | Public keys | Modern high-performance VPN |
| PPTP | TCP 1723 | MPPE (weak) | MS-CHAPv2 | Legacy — avoid in production |
PPTP is considered insecure. IKEv2/IPsec and SSL VPN are the current recommended options.
About these practice questions
One of 320 original KCSA practice questions on Courseiva, each with a full explanation and wrong-answer analysis — not exam dumps or protected exam content. Learn why practice questions differ from exam dumps →
JA
Written and reviewed by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
Last reviewed August 2026 · checked against the official CNCF / Linux Foundation exam blueprint
This KCSA practice question is part of Courseiva's free CNCF / Linux Foundation certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the KCSA exam.