Courseiva
← SC-100
Full test
Question 540 of 969
Design security solutions for infrastructure →mediumMultiple ChoiceObjective-mapped

Quick Answer

The answer is that allowing HTTP (port 80) to *.microsoft.com is unnecessary and could be exploited. This is a security issue because HTTPS on port 443 already provides encrypted communication, so permitting unencrypted HTTP traffic to Microsoft domains exposes data to potential interception or manipulation in transit, violating the principle of least privilege. On the Microsoft Cybersecurity Architect exam, this scenario tests your ability to identify overly permissive firewall rules that bypass encryption requirements, often appearing as a trap where candidates focus on the wildcard subdomain rather than the protocol itself. A common memory tip is to remember that in Azure Firewall, if you need secure web traffic, always block port 80 and allow only port 443—think “HTTP is the hole, HTTPS is the whole.”

SC-100 Design security solutions for infrastructure Practice Question

This SC-100 practice question tests your understanding of design security solutions for infrastructure. The scenario asks you to isolate a root cause — eliminate options that address a different problem before choosing. 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.

Exhibit

Refer to the exhibit.
```json
{
  "type": "Microsoft.Network/azureFirewalls",
  "apiVersion": "2023-02-01",
  "name": "hub-firewall",
  "location": "eastus",
  "properties": {
    "sku": {
      "name": "AZFW_VNet",
      "tier": "Standard"
    },
    "applicationRuleCollections": [
      {
        "name": "allow-web",
        "priority": 100,
        "action": {
          "type": "Allow"
        },
        "rules": [
          {
            "name": "allow-msft",
            "sourceAddresses": ["10.0.0.0/16"],
            "targetFqdns": ["*.microsoft.com"],
            "protocols": [
              {
                "protocolType": "Http",
                "port": 80
              },
              {
                "protocolType": "Https",
                "port": 443
              }
            ]
          }
        ]
      }
    ],
    "networkRuleCollections": [],
    "natRuleCollections": []
  }
}
```

Refer to the exhibit. An administrator is deploying an Azure Firewall using the ARM template snippet. After deployment, traffic from the 10.0.0.0/16 subnet to www.microsoft.com on HTTPS is allowed. What is a potential security issue with this configuration?

Question 1mediummultiple choice
Review the full subnetting walkthrough →

Exhibit

Refer to the exhibit.
```json
{
  "type": "Microsoft.Network/azureFirewalls",
  "apiVersion": "2023-02-01",
  "name": "hub-firewall",
  "location": "eastus",
  "properties": {
    "sku": {
      "name": "AZFW_VNet",
      "tier": "Standard"
    },
    "applicationRuleCollections": [
      {
        "name": "allow-web",
        "priority": 100,
        "action": {
          "type": "Allow"
        },
        "rules": [
          {
            "name": "allow-msft",
            "sourceAddresses": ["10.0.0.0/16"],
            "targetFqdns": ["*.microsoft.com"],
            "protocols": [
              {
                "protocolType": "Http",
                "port": 80
              },
              {
                "protocolType": "Https",
                "port": 443
              }
            ]
          }
        ]
      }
    ],
    "networkRuleCollections": [],
    "natRuleCollections": []
  }
}
```

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

✓

Allowing HTTP (port 80) to *.microsoft.com is unnecessary and could be exploited

The rule allows HTTP (port 80) to *.microsoft.com, which is unnecessary and could allow unencrypted traffic. HTTPS (port 443) is sufficient. Allowing HTTP could expose traffic to interception. Additionally, the rule allows all *.microsoft.com subdomains, which might be overly permissive, but the main issue is the inclusion of HTTP.

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.

  • ✗

    The priority of 100 is too high and could override other rules

    Why it's wrong here

    Incorrect: Priority 100 is typical and lower numbers are higher priority.

  • ✗

    The firewall SKU tier should be Premium for better security

    Why it's wrong here

    Incorrect: Standard tier provides sufficient application rule capabilities.

  • ✗

    The source address range is too broad

    Why it's wrong here

    Incorrect: The source range is the entire subnet, which is typical for a hub firewall.

  • ✓

    Allowing HTTP (port 80) to *.microsoft.com is unnecessary and could be exploited

    Why this is correct

    Correct: HTTP traffic is unencrypted and should not be needed for internal to Microsoft communication.

    Related concept

    CIDR notation defines the prefix length.

Common exam traps

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 media company stores terabytes of video archives that are accessed once a year for audit purposes. Moving these objects to a cold storage tier (Azure Archive, S3 Glacier, or Google Nearline) costs a fraction of hot storage. Questions like this test whether you understand storage tiers, access frequency tradeoffs, and retrieval latency requirements.

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 SC-100 subnetting questions on CIDR, address ranges, and subnet selection.

Related practice questions

Related SC-100 practice-question pages

Use these pages to review the topic behind this question. This is how one missed question becomes focused revision.

Design solutions that align with security best practices and priorities practice questions

Practise SC-100 questions linked to Design solutions that align with security best practices and priorities.

Design security operations, identity, and compliance capabilities practice questions

Practise SC-100 questions linked to Design security operations, identity, and compliance capabilities.

Design security solutions for infrastructure practice questions

Practise SC-100 questions linked to Design security solutions for infrastructure.

Design a Zero Trust strategy and architecture practice questions

Practise SC-100 questions linked to Design a Zero Trust strategy and architecture.

Design security solutions for applications and data practice questions

Practise SC-100 questions linked to Design security solutions for applications and data.

Evaluate GRC and security operations strategies practice questions

Practise SC-100 questions linked to Evaluate GRC and security operations strategies.

Design security for infrastructure practice questions

Practise SC-100 questions linked to Design security for infrastructure.

Design a strategy for data and applications practice questions

Practise SC-100 questions linked to Design a strategy for data and applications.

Recommend security best practices and priorities practice questions

Practise SC-100 questions linked to Recommend security best practices and priorities.

SC-100 fundamentals practice questions

Practise SC-100 questions linked to SC-100 fundamentals.

SC-100 scenario practice questions

Practise SC-100 questions linked to SC-100 scenario.

SC-100 troubleshooting practice questions

Practise SC-100 questions linked to SC-100 troubleshooting.

Practice this exam

Start a free SC-100 practice session

Short sessions build daily habit. Longer sessions build exam-day stamina. Try a timed session to simulate real conditions.

10 questions20 questions30 questions50 questionsTimed 30
SC-100 practice-test guide →Study guide →Browse all practice tests

FAQ

Questions learners often ask

What does this SC-100 question test?

Design security solutions for infrastructure — This question tests Design security solutions for infrastructure — CIDR notation defines the prefix length..

What is the correct answer to this question?

The correct answer is: Allowing HTTP (port 80) to *.microsoft.com is unnecessary and could be exploited — The rule allows HTTP (port 80) to *.microsoft.com, which is unnecessary and could allow unencrypted traffic. HTTPS (port 443) is sufficient. Allowing HTTP could expose traffic to interception. Additionally, the rule allows all *.microsoft.com subdomains, which might be overly permissive, but the main issue is the inclusion of HTTP.

What should I do if I get this SC-100 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 SC-100 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 →

How Courseiva writes practice questions · Editorial policy

Last reviewed: Jun 21, 2026

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.

Loading comments…

Sign in to join the discussion.

This SC-100 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 SC-100 exam.