Azure DNS basics - Step-by-Step Execution

Process Flow - Azure DNS basics

Create DNS Zone

↓

Add DNS Records

↓

DNS Zone Hosted in Azure

↓

Clients Query DNS

↓

Azure DNS Resolves Queries

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Clients Get IP Addresses

This flow shows how you create a DNS zone in Azure, add records, and how clients query Azure DNS to get IP addresses.

Execution Sample

Azure

az network dns zone create -g MyResourceGroup -n example.com
az network dns record-set a add-record -g MyResourceGroup -z example.com -n www -a 10.1.2.3

Creates a DNS zone named example.com and adds an A record for www.example.com pointing to IP 10.1.2.3.

Process Table

Step	Action	Resource Group	DNS Zone	Record Set	Record Type	Record Value	Result
1	Create DNS Zone	MyResourceGroup	example.com	-	-	-	DNS zone example.com created
2	Add A Record	MyResourceGroup	example.com	www	A	10.1.2.3	A record www.example.com -> 10.1.2.3 added
3	Client DNS Query	-	example.com	www	A	-	Azure DNS returns 10.1.2.3
4	Client DNS Query	-	example.com	mail	A	-	No record found, NXDOMAIN returned

💡 Execution stops after client queries show how Azure DNS resolves or fails to resolve records.

Status Tracker

Variable	Start	After Step 1	After Step 2	After Step 3	After Step 4
DNS Zone	None	example.com created	example.com exists	example.com exists	example.com exists
Record Set www	None	None	A record with IP 10.1.2.3	A record with IP 10.1.2.3	A record with IP 10.1.2.3
Record Set mail	None	None	None	None	None

Key Moments - 3 Insights

Why does the client get NXDOMAIN for mail.example.com?

Because no A record was added for 'mail' in the DNS zone, Azure DNS returns NXDOMAIN as shown in execution_table step 4.

What happens if you create a DNS zone but add no records?

Clients querying any record will get NXDOMAIN because no records exist, similar to step 4 in the execution_table.

Does creating a DNS zone automatically create records?

No, creating a DNS zone only sets up the container. Records must be added separately as shown in step 2.

Visual Quiz - 3 Questions

Look at the execution_table, what IP address does Azure DNS return for www.example.com at step 3?

A 10.0.0.1

B NXDOMAIN

C 10.1.2.3

D No response

💡 Hint

Check the 'Record Value' and 'Result' columns in step 3 of execution_table.

At which step does the DNS zone example.com get created?

A Step 2

B Step 1

C Step 3

D Step 4

💡 Hint

Look at the 'Action' column in execution_table for when the DNS zone is created.

If you add an A record for mail.example.com with IP 10.2.3.4, what changes in variable_tracker after step 4?

A Record Set mail changes from None to A record with IP 10.2.3.4

B DNS Zone changes from example.com to None

C Record Set www changes to None

D No changes occur

💡 Hint

Refer to the 'Record Set mail' row in variable_tracker to see how records update.

Concept Snapshot

Azure DNS basics:
- Create a DNS zone to hold your domain records.
- Add DNS records (A, CNAME, etc.) to the zone.
- Azure DNS hosts the zone and answers queries.
- Clients query Azure DNS to resolve domain names to IPs.
- No records means queries return NXDOMAIN.

Full Transcript

This visual execution shows how Azure DNS works step-by-step. First, you create a DNS zone in a resource group. Then you add DNS records like A records to that zone. Azure DNS hosts the zone and answers client queries. When a client asks for www.example.com, Azure DNS returns the IP address from the A record. If a record does not exist, Azure DNS returns NXDOMAIN. Variables track the DNS zone and records state after each step. Key moments clarify common confusions about missing records and zone creation. The quiz tests understanding of the DNS zone creation, record addition, and query results.

Practice

1. What is the main purpose of Azure DNS?

easy

A. To monitor network traffic in real-time

B. To store files and documents securely

C. To run virtual machines in the cloud

D. To manage domain names and translate them to IP addresses

Solution

1. Step 1: Understand Azure DNS role

   Azure DNS is used to manage domain names and their records inside Azure.

2. Step 2: Identify main function

   It translates domain names into IP addresses so users can find services on the internet.

3. Final Answer:

   To manage domain names and translate them to IP addresses -> Option D

4. Quick Check:

   Azure DNS = Domain name management [OK]

Hint: Azure DNS handles domain names, not files or VMs [OK]

Common Mistakes:

• Confusing DNS with storage services
• Thinking Azure DNS runs virtual machines
• Mixing DNS with network monitoring

2. Which of the following is the correct way to create a DNS zone in Azure CLI?

easy

A. az network dns zone create -g MyResourceGroup -n example.com

B. az dns create zone -g MyResourceGroup -n example.com

C. az network create dnszone -g MyResourceGroup -n example.com

D. az dns zone new -g MyResourceGroup -n example.com

Solution

1. Step 1: Recall Azure CLI syntax for DNS zone creation

   The correct command uses 'az network dns zone create' with resource group and zone name.

2. Step 2: Compare options

   Only az network dns zone create -g MyResourceGroup -n example.com matches the correct Azure CLI syntax for creating a DNS zone.

3. Final Answer:

   az network dns zone create -g MyResourceGroup -n example.com -> Option A

4. Quick Check:

   Correct Azure CLI DNS zone command = az network dns zone create -g MyResourceGroup -n example.com [OK]

Hint: Remember 'az network dns zone create' for DNS zones [OK]

Common Mistakes:

• Using incorrect command verbs like 'new' or 'create zone'
• Omitting 'network' in the command
• Mixing up command order or parameters

3. Given this Azure CLI command:
az network dns record-set a add-record -g MyRG -z example.com -n www -a 10.0.0.1
What does this command do?

medium

A. Creates a DNS zone named 'www' in resource group MyRG

B. Creates an A record named 'www' pointing to IP 10.0.0.1 in example.com zone

C. Deletes the A record named 'www' in example.com zone

D. Adds a CNAME record pointing 'www' to 10.0.0.1

Solution

1. Step 1: Analyze command components

   The command adds an A record ('-a') named 'www' with IP 10.0.0.1 to the DNS zone 'example.com' in resource group 'MyRG'.

2. Step 2: Confirm record type and action

   'add-record' means creating a record, and 'a' specifies an A record (IP address).

3. Final Answer:

   Creates an A record named 'www' pointing to IP 10.0.0.1 in example.com zone -> Option B

4. Quick Check:

   Command adds A record 'www' with IP 10.0.0.1 [OK]

Hint: A record = IP address, add-record means create [OK]

Common Mistakes:

• Confusing A record with CNAME
• Thinking the command deletes records
• Misreading '-n' as zone name instead of record name

4. You run this command to add a TXT record:
az network dns record-set txt add-record -g RG1 -z example.com -n info -v "verification=12345"
But it fails with an error. What is the likely cause?

medium

A. The '-v' parameter is invalid; it should be '-a' for TXT records

B. The record name '-n' cannot be 'info' for TXT records

C. The TXT record value must be enclosed in single quotes, not double quotes

D. The resource group name 'RG1' is missing

Solution

1. Step 1: Check TXT record syntax

   TXT record values often require single quotes to avoid shell parsing errors.

2. Step 2: Identify error cause

   Using double quotes can cause the shell to misinterpret the value, leading to failure.

3. Final Answer:

   The TXT record value must be enclosed in single quotes, not double quotes -> Option C

4. Quick Check:

   Use single quotes for TXT values to avoid errors [OK]

Hint: Use single quotes for TXT record values in CLI [OK]

Common Mistakes:

• Using wrong parameter '-a' instead of '-v' for TXT
• Assuming record name restrictions incorrectly
• Ignoring resource group existence

5. You want to create a DNS zone for your domain 'myapp.com' and add two records: an A record for 'app' pointing to 192.168.1.10 and a CNAME record for 'www' pointing to 'app.myapp.com'. Which sequence of Azure CLI commands correctly achieves this?

hard

A. 1) az network dns zone create -g RG -n myapp.com2) az network dns record-set a add-record -g RG -z myapp.com -n app -a 192.168.1.103) az network dns record-set cname set-record -g RG -z myapp.com -n www -c app.myapp.com

B. 1) az network dns zone create -g RG -n myapp.com2) az network dns record-set cname add-record -g RG -z myapp.com -n app -c 192.168.1.103) az network dns record-set a set-record -g RG -z myapp.com -n www -a app.myapp.com

C. 1) az dns zone create -g RG -n myapp.com2) az network dns record-set a add-record -g RG -z myapp.com -n app -a 192.168.1.103) az network dns record-set cname add-record -g RG -z myapp.com -n www -c app.myapp.com

D. 1) az network dns zone create -g RG -n myapp.com2) az network dns record-set a add-record -g RG -z myapp.com -n app -a 192.168.1.103) az network dns record-set cname add-record -g RG -z myapp.com -n www -a app.myapp.com

Solution

1. Step 1: Create DNS zone

   Use 'az network dns zone create' with resource group and domain name to create the zone.

2. Step 2: Add A record for 'app'

   Use 'az network dns record-set a add-record' with correct parameters to add IP address record.

3. Step 3: Add CNAME record for 'www'

   Use 'az network dns record-set cname set-record' to point 'www' to 'app.myapp.com'.

4. Final Answer:

   1) az network dns zone create -g RG -n myapp.com
   2) az network dns record-set a add-record -g RG -z myapp.com -n app -a 192.168.1.10
   3) az network dns record-set cname set-record -g RG -z myapp.com -n www -c app.myapp.com -> Option A

5. Quick Check:

   Zone create + A record + CNAME set-record = 1) az network dns zone create -g RG -n myapp.com
   2) az network dns record-set a add-record -g RG -z myapp.com -n app -a 192.168.1.10
   3) az network dns record-set cname set-record -g RG -z myapp.com -n www -c app.myapp.com [OK]

Hint: Use 'add-record' for A, 'set-record' for CNAME [OK]

Common Mistakes:

• Using wrong commands like 'az dns zone create'
• Mixing up 'add-record' and 'set-record' for CNAME
• Assigning IP to CNAME record