ICA Advanced Scenarios Practice Question
In a multi-cluster Istio setup, you notice that service 'A' in cluster 1 cannot communicate with service 'B' in cluster 2, even though 'Cross-Cluster' is enabled. The logs show '404 Not Found'. What is the most likely reason?
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
✓
Service 'B' is not exported to the local cluster via an ExportTo policy.
Even with multi-cluster discovery, services must be explicitly defined in the mesh registry via ServiceEntry, or the internal DNS name must be resolvable.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✓
Service 'B' is not exported to the local cluster via an ExportTo policy.
Why this is correct
Istio requires services to be explicitly exported to other namespaces or clusters using 'exportTo' in the Service/Gateway configurations.
- ✗
The sidecar image versions differ.
Why it's wrong here
Istio supports sidecar versioning; this does not cause 404s.
- ✗
The cluster network is not configured in meshConfig.
Why it's wrong here
This would likely cause connection timeouts, not 404s.
- ✗
The istio-ingressgateway is not installed.
Why it's wrong here
The ingress gateway is usually required for cross-cluster, but a 404 suggests a routing/resolution issue, not a missing gateway.
Visual reference
About these practice questions
One of 292 original ICA 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 ICA 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 ICA exam.