1Z0-997-26 Workload Migration Practice Question
Your organization is performing a zero-downtime database migration from an Oracle Database on-premises to OCI Exadata Database Service using Oracle Zero Downtime Migration (ZDM). During the migration job execution, the workflow pauses during the dataguard broker configuration step. Reviewing the ZDM logs, you find a network timeout error communicating between the ZDM service host and the OCI database listener. What is the most likely cause?
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
✓
OCI VCN Security Lists or Network Security Groups block incoming TCP port 1521 or SSH port 22 from the ZDM client subnet.
ZDM orchestrates migrations by communicating over SSH and Oracle SQL*Net (port 1521) between the ZDM service host, the on-premises database, and the OCI database. Security lists, network security groups, or firewalls blocking port 1521 or SSH will cause communication timeouts.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
OCI Object Storage bucket policies prevent ZDM from reading temporary backup files.
Why it's wrong here
Object storage bucket policies affect storage access, not SQL*Net listener connectivity timeouts.
- ✓
OCI VCN Security Lists or Network Security Groups block incoming TCP port 1521 or SSH port 22 from the ZDM client subnet.
Why this is correct
ZDM requires bidirectional communication over SSH (22) and SQL*Net (1521) for orchestration and Data Guard setup.
- ✗
The Exadata database service requires Autonomous Database credentials to establish connection.
Why it's wrong here
Exadata Database Service uses standard database credentials, not Autonomous Database mTLS wallets by default for ZDM.
- ✗
OCI IAM quotas restrict the creation of more than 10 Data Guard associations per tenancy.
Why it's wrong here
IAM quotas govern resource counts, not network socket timeouts.
About these practice questions
Courseiva writes every 1Z0-997-26 question from scratch — 344 in total, each with an explanation and a wrong-answer breakdown. None are copied from real exams or dumps. 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 Oracle exam blueprint
This 1Z0-997-26 practice question is part of Courseiva's free Oracle 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 1Z0-997-26 exam.