CKA Services and Networking Practice Question
What is the default kube-proxy mode in Kubernetes v1.29?
⚠ Common exam trap
Watch out — candidates often confuse the default mode with the most advanced or performant option (like ipvs), or mistakenly think nftables is the default because it is the modern replacement for iptables in Linux, but Kubernetes v1.29 still defaults to iptables.
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
✓
iptables
In Kubernetes v1.29, the default kube-proxy mode is `iptables`. This mode uses Linux iptables rules to handle service traffic, providing better performance and reliability than the older userspace mode. It is the default because it balances simplicity and efficiency for most cluster configurations.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
nftables
Why it's wrong here
nftables is the modern Linux kernel packet-classification framework that replaces iptables, but it is not a kube-proxy operating mode. As of Kubernetes v1.29, kube-proxy offers only three modes: userspace (deprecated), iptables, and ipvs. The default remains the iptables mode, which configures legacy netfilter rules. Therefore, selecting nftables as a kube-proxy mode is incorrect.
- ✗
userspace
Why it's wrong here
The userspace mode was kube-proxy's original implementation, where traffic is processed in user space and then re-injected into the kernel, causing significant overhead and latency. This mode is deprecated and has been replaced by the iptables mode, which handles traffic entirely in kernel space. In v1.29, userspace is not the default and is only retained for backward compatibility in very old clusters.
- ✓
iptables
Why this is correct
iptables is the default kube-proxy mode in Kubernetes v1.29, using legacy netfilter rules to implement Service load balancing. kube-proxy programs iptables chains with rules that use the statistic matching module to select backend Pods with random probability. This approach provides efficient in-kernel NAT and load balancing without requiring a separate proxy process for each connection, which is why it remains the standard.
- ✗
ipvs
Why it's wrong here
ipvs is an alternative kube-proxy mode that leverages the Linux IPVS kernel module, which supports multiple load-balancing algorithms such as round-robin, least-connection, and consistent hashing. While ipvs offers better scalability and performance for large clusters, it is not enabled by default. To use ipvs, you must explicitly set --proxy-mode=ipvs when starting kube-proxy, so it is incorrect to state that it is the default in v1.29.
Go deeper
Related to this question
Learn chapter
Kubernetes Architecture Overview
Key term
Ingress Resources
Ingress Resources are Kubernetes API objects that manage external access to services inside a cluster, typically HTTP and HTTPS traffic, by defining rules for routing requests based on hostnames and paths.
Key term
Network Policies
A Kubernetes resource that controls how pods communicate with each other and with other network endpoints, acting as a firewall for pod-to-pod traffic.
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Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This CKA practice question is part of Courseiva's free CNCF 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 CKA exam.