The correct answer is to use `terraform import` to bring the existing security group into Terraform state. This is the proper approach because `terraform import` maps a real-world resource—such as the manually created security group in AWS—to a resource block in your configuration, allowing Terraform to track and manage it without recreating it. Simply running `terraform apply` would attempt to create a duplicate, while manually editing the state file is error-prone and unsupported. On the HashiCorp Terraform Associate TF-003 exam, this question tests your understanding of state management and the distinction between `import`, `refresh`, and `apply`. A common trap is confusing `terraform refresh` with import; remember that refresh only updates existing state attributes, it does not add new resources. For a quick memory tip: think of `import` as "adopting" an existing resource into Terraform’s control, not rebuilding it.
TF-003 Read, generate and modify configuration Practice Question
This TF-003 practice question tests your understanding of read, generate and modify configuration. This is a configuration task: choose the command set that satisfies every stated requirement. Small differences — like 'secret' vs 'password' or 'transport input ssh' vs 'all' — change whether the answer is correct. After answering, compare your reasoning against the explanation and wrong-answer breakdown below. Once you have made your selection, read the full explanation to reinforce the concept and understand why each distractor is designed to mislead on exam day.
A team is using Terraform to manage a multi-tier application on AWS. The configuration includes resources for VPC, subnets, security groups, and EC2 instances. Recently, a developer manually created an additional security group in the AWS console for testing, and now the team wants to manage it via Terraform. They have updated the configuration to include this security group with the same name and rules. When they run `terraform plan`, it shows that the security group will be created, but the existing one is not detected. They want to bring the existing security group under Terraform management without recreating it. The team is using a remote backend with state locking. What should they do?
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Use `terraform import` to import the existing security group into state.
Option C is correct because `terraform import` is the proper way to bring existing resources into Terraform state. Option A is wrong because simply running apply would try to create a duplicate. Option B is wrong because manually editing the state file is error-prone and not recommended. Option D is wrong because `terraform refresh` refreshes state, but does not import new resources.
Key principle: Count usable hosts — not total addresses — and remember that the network and broadcast addresses are not available to hosts in standard IPv4 subnets.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
✗
Run `terraform apply` and then modify the state to remove the duplicate.
Why it's wrong here
will create a duplicate resource and cause conflict
✗
Manually edit the Terraform state file to add the security group.
Why it's wrong here
prone to errors and not a best practice
✗
Run `terraform refresh` to update the state with the existing resource.
Why it's wrong here
refresh only updates attributes, does not add new resources
✓
Use `terraform import` to import the existing security group into state.
Common exam trap: usable hosts are not the same as total addresses
Subnetting questions often tempt you into counting all addresses. In normal IPv4 subnets, the network and broadcast addresses are not usable host addresses.
Detailed technical explanation
How to think about this question
Subnetting questions test whether you can identify the network, broadcast address, usable range, mask and correct subnet. Slow down enough to calculate the block size correctly.
KKey Concepts to Remember
CIDR notation defines the prefix length.
Block size helps identify subnet boundaries.
Network and broadcast addresses are not usable hosts in normal IPv4 subnets.
The required host count determines the smallest suitable subnet.
TExam Day Tips
→Write the block size before choosing the subnet.
→Check whether the question asks for hosts, subnets or a specific address range.
→Do not confuse /24, /25, /26 and /27 host counts.
Key takeaway
Count usable hosts — not total addresses — and remember that the network and broadcast addresses are not available to hosts in standard IPv4 subnets.
Real-world example
How this comes up in practice
A network engineer segments a warehouse floor into three subnets: 20 scanners, 5 printers, and 2 management hosts. Picking the wrong mask wastes addresses or leaves too few usable hosts. Exam questions test whether you can apply CIDR notation, calculate block size, and identify the correct usable-host range for a given prefix.
What to study next
Got this wrong? Here's your next step.
Review block sizes, usable host formulas (2^n − 2), and how to find network and broadcast addresses for /24 through /30. Then practise related TF-003 subnetting questions on CIDR, address ranges, and subnet selection.
Read, generate and modify configuration — This question tests Read, generate and modify configuration — CIDR notation defines the prefix length..
What is the correct answer to this question?
The correct answer is: Use `terraform import` to import the existing security group into state. — Option C is correct because `terraform import` is the proper way to bring existing resources into Terraform state. Option A is wrong because simply running apply would try to create a duplicate. Option B is wrong because manually editing the state file is error-prone and not recommended. Option D is wrong because `terraform refresh` refreshes state, but does not import new resources.
What should I do if I get this TF-003 question wrong?
Review block sizes, usable host formulas (2^n − 2), and how to find network and broadcast addresses for /24 through /30. Then practise related TF-003 subnetting questions on CIDR, address ranges, and subnet selection.
What is the key concept behind this question?
CIDR notation defines the prefix length.
About these practice questions
Courseiva creates original exam-style practice questions with explanations and wrong-answer analysis. It does not publish real exam questions, exam dumps, or protected exam content. Learn why practice questions differ from exam dumps →
These questions test the same concept from different angles. Work through them to make sure you can recognise it however the exam phrases it.
Variation 1. A team has an existing S3 bucket created outside Terraform. They want to manage it with Terraform by importing its state. Which of the following is the correct sequence of commands to read the bucket's configuration and avoid drift?
hard
A.Run terraform refresh, then terraform state pull to generate configuration.
B.Run terraform plan, note the resource address, then run terraform import.
C.Run terraform import, then terraform state show to generate configuration.
✓ D.Write a minimal resource configuration, run terraform import, then terraform plan, then adjust configuration to match state.
Why D: Option C is correct: first write a minimal resource block, then import, then run terraform plan to detect drift, then adjust config to match. Option A is wrong because terraform import requires a configuration to exist. Option B is wrong because terraform plan before import will show nothing. Option D is wrong because terraform refresh alone does not create a state entry for unmanaged resources.
Last reviewed: Jun 24, 2026
Question Discussion
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This TF-003 practice question is part of Courseiva's free HashiCorp 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 TF-003 exam.
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