Quick Answer
The answer is a network security group (NSG). An NSG is the correct Azure feature because it acts as a stateful, distributed firewall that filters traffic to and from Azure resources in a virtual network, using security rules that evaluate source IP address, destination port, and protocol (TCP, UDP, or ICMP) to allow or deny traffic. On the AZ-104 exam, this concept tests your understanding of network security controls at the subnet or NIC level, often appearing in scenario-based questions where you must choose between an NSG and Azure Firewall—a common trap is selecting Azure Firewall for simple IP/port filtering when an NSG is sufficient and more cost-effective. Remember the memory tip: NSG = Network Security Gateway, focusing on IP, port, and protocol at the subnet or NIC boundary, while Azure Firewall handles higher-level application filtering and centralized logging.
This AZ-104 practice question tests your understanding of implement and manage virtual networking. Match the stated requirement to the specific cloud service, access model, or configuration option — many options are valid in isolation but not for this scenario. 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.
You need to allow or deny traffic to and from resources in an Azure subnet based on source IP address, destination port, and protocol. Which Azure feature should you use?
A network security group
NSGs are used to allow or deny network traffic by rule.
A route table
Why wrong: A route table controls where traffic is sent, not whether it is allowed or denied.
A private DNS zone
Why wrong: A private DNS zone handles name resolution, not filtering.
Azure Advisor
Why wrong: Azure Advisor provides recommendations and does not enforce traffic rules.
Answer choices
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
A network security group
A network security group (NSG) is the correct Azure feature because it acts as a stateful, distributed firewall that filters traffic to and from Azure resources in a virtual network. NSGs contain security rules that allow or deny inbound and outbound traffic based on source/destination IP address, port, and protocol (TCP, UDP, or ICMP). This directly matches the requirement to control traffic based on source IP, destination port, and protocol.
Key principle: Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Answer analysis
For each option: why learners choose it and why it is or isn't the right answer here.
A network security group
Why this is correct
NSGs are used to allow or deny network traffic by rule.
Related concept
Read the scenario before looking for a memorised answer.
A route table
Why it's wrong here
A route table controls where traffic is sent, not whether it is allowed or denied.
A private DNS zone
Why it's wrong here
A private DNS zone handles name resolution, not filtering.
Azure Advisor
Why it's wrong here
Azure Advisor provides recommendations and does not enforce traffic rules.
Common exam traps
The trap here is that candidates often confuse route tables (which control traffic paths) with NSGs (which control traffic permissions), especially when the question mentions 'allow or deny traffic'—route tables never deny traffic, they only redirect it.
Detailed technical explanation
NSG rules are evaluated in priority order (lowest number first) and are stateful—if an inbound rule allows traffic, the outbound response is automatically allowed regardless of outbound rules. Each rule specifies source/destination IP address ranges (CIDR), port ranges, and protocol (TCP, UDP, or * for all). NSGs can be associated with a subnet (applying to all resources in that subnet) or directly to a NIC (applying only to that specific VM). A common real-world scenario is locking down a web server subnet to only allow inbound HTTP/HTTPS from the internet while denying all other inbound traffic.
Key takeaway
Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Real-world example
A healthcare organisation deploys an application with a public-facing web tier and a private database tier. The database subnet has no public IP and only accepts connections from the web tier's security group. Questions like this test whether you can design cloud network isolation using VNets/VPCs, subnets, and security group rules.
What to study next
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
Implement and Manage Virtual Networking — study guide chapter
Learn the concepts, then practise the questions
Implement and Manage Virtual Networking practice questions
Targeted practice on this topic area only
All AZ-104 questions
1,170 questions across all exam domains
AZ-104 study guide
Full concept coverage aligned to exam objectives
AZ-104 practice test guide
How to use practice tests most effectively before exam day
Related practice questions
Use these pages to review the topic behind this question. This is how one missed question becomes focused revision.
Practise AZ-104 questions linked to Manage Azure Identities and Governance.
Practise AZ-104 questions linked to Implement and Manage Storage.
Practise AZ-104 questions linked to Deploy and Manage Azure Compute.
Practise AZ-104 questions linked to Implement and Manage Virtual Networking.
Practise AZ-104 questions linked to Monitor and Maintain Azure Resources.
Practise AZ-104 questions linked to AZ-104 Azure RBAC.
Practise AZ-104 questions linked to AZ-104 storage account.
Practise AZ-104 questions linked to AZ-104 virtual network.
Practise AZ-104 questions linked to AZ-104 NSG.
Practise AZ-104 questions linked to AZ-104 Azure Monitor.
Practise AZ-104 questions linked to AZ-104 backup.
Practise AZ-104 questions linked to AZ-104 managed identity.
Practice this exam
Short sessions build daily habit. Longer sessions build exam-day stamina. Try a timed session to simulate real conditions.
FAQ
Implement and Manage Virtual Networking — This question tests Implement and Manage Virtual Networking — Read the scenario before looking for a memorised answer..
The correct answer is: A network security group — A network security group (NSG) is the correct Azure feature because it acts as a stateful, distributed firewall that filters traffic to and from Azure resources in a virtual network. NSGs contain security rules that allow or deny inbound and outbound traffic based on source/destination IP address, port, and protocol (TCP, UDP, or ICMP). This directly matches the requirement to control traffic based on source IP, destination port, and protocol.
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
Read the scenario before looking for a memorised answer.
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 →
Same concept, more angles
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. You need to control inbound and outbound traffic to resources in a subnet by allowing or denying traffic based on IP address, port, and protocol. Which Azure feature should you use?
mediumWhy A: A network security group (NSG) is the correct Azure feature because it contains security rules that allow or deny inbound and outbound traffic at the subnet or network interface level based on source/destination IP address, port, and protocol (TCP, UDP, or Any). This directly matches the requirement to control traffic by these three parameters.
Last reviewed: Jun 11, 2026
This AZ-104 practice question is part of Courseiva's free Microsoft 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 AZ-104 exam.
Question Discussion
Share a tip, memory trick, or ask about the reasoning behind this question. Do not post real exam questions, leaked content, braindumps, or copyrighted exam material. Comments are moderated and may be removed without notice.
Sign in to join the discussion.