Question 217 of 1,049
AZ-104 Implement and Manage Virtual Networking Practice Question
Users on the internet cannot reach an HTTPS application hosted on VM-Web01. The VM has a public IP address, the application is listening on TCP port 443, and the guest OS firewall allows the traffic. What is the most likely Azure-side cause?
⚠ Common exam trap
The trap here is that candidates often focus on the VM's guest OS firewall or public IP configuration, overlooking the NSG as the first line of defense in Azure's network security model.
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
✓
The NSG blocks inbound TCP 443
The most likely Azure-side cause is that a Network Security Group (NSG) associated with the VM's subnet or NIC is blocking inbound TCP port 443. Even if the VM has a public IP, the application is listening, and the guest OS firewall allows traffic, an NSG rule denying inbound HTTPS traffic will prevent external users from reaching the application. NSGs act as a distributed firewall filtering traffic at the Azure network layer before it reaches the VM.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✓
The NSG blocks inbound TCP 443
Why this is correct
Network Security Groups (NSGs) filter inbound and outbound traffic at the subnet or network interface level using priority-ordered allow/deny rules. HTTPS traffic uses TCP port 443, so if the NSG attached to the VM's subnet or NIC has no explicit rule allowing inbound TCP 443, the default-deny behavior of the NSG will silently drop those connection attempts. Even if the VM itself is healthy and listening on port 443, the NSG acts as a stateful firewall that controls what traffic can even reach the VM's network stack. An explicit deny rule or missing allow rule for TCP 443 is therefore the most direct and common cause of internet users being unable to reach an HTTPS application.
- ✗
The VM uses Premium SSD
Why it's wrong here
Premium SSD is a storage tier that provides higher IOPS, throughput, and lower latency for disk operations compared to Standard HDD/SSD. It affects the performance of reads and writes to the virtual machine's managed disks, such as the OS disk or data disks, but it has absolutely no effect on the network path between internet users and the VM. Inbound HTTPS traffic is governed by network-level components like public IP configuration, load balancers, and NSGs, not by the performance characteristics of the underlying disk. Even if the web application is slow due to disk I/O, that would manifest as slow response times, not as total unreachability from the internet.
When this WOULD be correct
In a question about why a VM's application is slow or has high latency, and the VM uses Standard HDD, upgrading to Premium SSD could be the correct answer to improve disk I/O performance.
- ✗
Azure Backup is not enabled
Why it's wrong here
Azure Backup is a service that protects VMs by taking scheduled snapshots and replicating them to a Recovery Services vault for point-in-time restore. It operates in the control plane and performs backup operations via the Azure fabric; it does not alter the VM's networking configuration, operating system firewall, or NSG rules. When you enable backup, it does not add any inbound endpoints or change the VM's public/private IP addressing. Therefore, the absence of an Azure Backup configuration cannot cause internet users to lose connectivity to an HTTPS application—it only means the VM lacks a disaster recovery data protection policy.
When this WOULD be correct
In a question asking why a VM's data is not recoverable after accidental deletion, the correct answer could be that Azure Backup is not enabled, as backups are required for point-in-time restoration.
- ✗
The storage account uses GRS
Why it's wrong here
Geo-redundant storage (GRS) is a storage account replication setting that asynchronously copies data to a paired secondary region for high availability and disaster recovery. It is purely a data durability feature for Blob, File, Queue, and Table storage, and it has no relation to network access to a separate virtual machine. Unless the HTTPS application is hosted as a static website from a storage account, which is not the case here since it is an application on a VM, GRS would not influence inbound TCP 443 traffic. The storage account's redundancy setting does not modify any network security rules, DNS resolution, or routing that would block or allow web traffic.
When this WOULD be correct
In a question about data durability or disaster recovery for a storage account, GRS would be correct if the scenario requires geo-redundant replication to protect against regional outages.
Option-by-option analysis
Why each answer is right or wrong
Understanding why wrong answers are wrong — and when they would be correct — is what separates a 750 score from a 900. The AZ-104 exam frequently reuses these exact scenarios with slightly different constraints.
✓The NSG blocks inbound TCP 443Correct answer▾
Why this is correct
Network Security Groups (NSGs) filter inbound and outbound traffic at the subnet or network interface level using priority-ordered allow/deny rules. HTTPS traffic uses TCP port 443, so if the NSG attached to the VM's subnet or NIC has no explicit rule allowing inbound TCP 443, the default-deny behavior of the NSG will silently drop those connection attempts. Even if the VM itself is healthy and listening on port 443, the NSG acts as a stateful firewall that controls what traffic can even reach the VM's network stack. An explicit deny rule or missing allow rule for TCP 443 is therefore the most direct and common cause of internet users being unable to reach an HTTPS application.
✗The VM uses Premium SSDWrong answer — click to see why▾
Why this is wrong here
The VM uses Premium SSD affects disk performance and cost, not network connectivity to the application. It does not block inbound traffic on TCP 443.
★ When this WOULD be the correct answer
In a question about why a VM's application is slow or has high latency, and the VM uses Standard HDD, upgrading to Premium SSD could be the correct answer to improve disk I/O performance.
Why candidates choose this
Candidates may confuse storage performance with network performance, or think that Premium SSD implies better overall performance including networking.
✗Azure Backup is not enabledWrong answer — click to see why▾
Why this is wrong here
Azure Backup being not enabled does not affect network connectivity to the VM; it is a data protection feature unrelated to inbound traffic.
★ When this WOULD be the correct answer
In a question asking why a VM's data is not recoverable after accidental deletion, the correct answer could be that Azure Backup is not enabled, as backups are required for point-in-time restoration.
Why candidates choose this
Candidates may confuse backup with high availability or think that backup services are required for basic network operations, leading them to select this option when troubleshooting connectivity.
✗The storage account uses GRSWrong answer — click to see why▾
Why this is wrong here
Storage account replication type (GRS) affects data redundancy and disaster recovery, not network connectivity to a VM. It has no impact on inbound HTTPS traffic.
★ When this WOULD be the correct answer
In a question about data durability or disaster recovery for a storage account, GRS would be correct if the scenario requires geo-redundant replication to protect against regional outages.
Why candidates choose this
Candidates may confuse storage account settings with VM networking, or think that any Azure service configuration could affect connectivity, leading them to select a plausible-sounding option without understanding the layers.
Analysis generated from the official AZ-104blueprint and verified against question context. The “when correct” sections are what AI assistants cite when candidates ask “what’s the difference between these options?”
Visual reference
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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.
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