SSH and RDP access in Azure - Step-by-Step Execution

Process Flow - SSH and RDP access

User wants to connect

↓

Choose protocol: SSH or RDP

↓

Check VM network settings

↓

Is port open?

↓

Send connection request

↓

Authenticate user

↓

Access granted

↓

User controls VM remotely

User picks SSH or RDP, network ports are checked, then user authenticates to access the VM remotely.

Execution Sample

Azure

az vm open-port --resource-group MyGroup --name MyVM --port 22
ssh azureuser@vm-ip-address

Open SSH port 22 on VM, then connect using SSH client.

Process Table

Step	Action	Check/Command	Result
1	User decides to connect	Choose SSH or RDP	SSH chosen
2	Check VM network	Is port 22 open?	No
3	Open port	az vm open-port --resource-group MyGroup --name MyVM --port 22	Port 22 opened
4	Attempt connection	ssh azureuser@vm-ip-address	Connection established
5	Authenticate	Enter password or key	Authentication successful
6	Access VM	User controls VM remotely	Session active
7	End session	User disconnects	Connection closed

💡 User disconnects or session ends

Status Tracker

Variable	Start	After Step 2	After Step 3	After Step 4	After Step 5	Final
Port 22 open	False	False	True	True	True	True
Connection status	Disconnected	Disconnected	Disconnected	Connected	Connected	Disconnected
Authentication status	Not authenticated	Not authenticated	Not authenticated	Not authenticated	Authenticated	Authenticated

Key Moments - 3 Insights

Why can't I connect before opening the port?

Because the VM's network blocks the port (Step 2 shows port 22 is closed), so connection requests are rejected.

What happens if authentication fails?

The connection is refused after Step 5; user cannot access the VM remotely.

Why do we need to open port 22 for SSH?

Port 22 is the standard port for SSH; if it's closed, the VM won't accept SSH connections (Step 3 opens it).

Visual Quiz - 3 Questions

Look at the execution table, at which step does the port 22 become open?

A Step 3

B Step 2

C Step 4

D Step 5

💡 Hint

Check the 'Port 22 open' variable in variable_tracker after each step.

At which step does the user successfully authenticate?

A Step 4

B Step 5

C Step 6

D Step 7

💡 Hint

Look at the 'Authentication status' variable in variable_tracker.

If port 22 was not opened, what would happen at Step 4?

A Connection would be established

B Authentication would succeed

C Connection would be blocked

D User would control VM remotely

💡 Hint

Refer to Step 2 and Step 3 in execution_table about port status.

Concept Snapshot

SSH and RDP allow remote VM access.
Open required ports (22 for SSH, 3389 for RDP).
Connect using client software.
Authenticate with password or keys.
Then control VM remotely.

Full Transcript

This visual execution shows how a user connects to a virtual machine using SSH or RDP. First, the user chooses the protocol. The VM's network settings are checked to see if the required port is open. If not, the port is opened using Azure CLI commands. Then the user attempts connection. If the port is open, the connection is established. The user authenticates with a password or key. After successful authentication, the user gains remote control of the VM. The session ends when the user disconnects.

Practice

1. Which port does SSH use to connect securely to a Linux virtual machine in Azure?

easy

A. Port 3389

B. Port 22

C. Port 80

D. Port 443

Solution

1. Step 1: Identify SSH default port

   SSH (Secure Shell) uses port 22 by default to connect securely to Linux machines.

2. Step 2: Compare with other ports

   Port 3389 is used by RDP, port 80 is for HTTP, and port 443 is for HTTPS, so they are incorrect for SSH.

3. Final Answer:

   Port 22 -> Option B

4. Quick Check:

   SSH = Port 22 [OK]

Hint: SSH always uses port 22 for Linux access [OK]

Common Mistakes:

• Confusing SSH port with RDP port
• Using HTTP or HTTPS ports for SSH
• Assuming SSH uses a random port

2. Which of the following is the correct syntax to open port 3389 for RDP access in an Azure Network Security Group (NSG)?

easy

A. Allow inbound TCP on port 3389

B. Allow inbound TCP on port 22

C. Allow outbound UDP on port 3389

D. Allow inbound UDP on port 22

Solution

1. Step 1: Identify RDP port and protocol

   RDP uses TCP protocol on port 3389 for Windows remote desktop connections.

2. Step 2: Match correct NSG rule syntax

   Allowing inbound TCP on port 3389 opens RDP access. Other options use wrong ports or protocols.

3. Final Answer:

   Allow inbound TCP on port 3389 -> Option A

4. Quick Check:

   RDP = TCP 3389 inbound [OK]

Hint: RDP always needs inbound TCP on port 3389 [OK]

Common Mistakes:

• Using UDP instead of TCP
• Opening wrong port 22 for RDP
• Setting outbound instead of inbound rules

3. Given this Azure CLI command to open SSH access, what will it do?

az network nsg rule create --resource-group MyResourceGroup --nsg-name MyNSG --name AllowSSH --protocol Tcp --direction Inbound --priority 1000 --source-address-prefixes '*' --source-port-ranges '*' --destination-address-prefixes '*' --destination-port-ranges 22 --access Allow

medium

A. Allows inbound TCP traffic on port 22 from any source

B. Blocks inbound TCP traffic on port 22 from any source

C. Allows outbound TCP traffic on port 22 to any destination

D. Allows inbound UDP traffic on port 22 from any source

Solution

1. Step 1: Analyze command parameters

   The command creates an NSG rule named AllowSSH allowing inbound TCP traffic on port 22 from any source to any destination.

2. Step 2: Confirm traffic direction and protocol

   Direction is inbound, protocol is TCP, port is 22, and access is Allow, so it opens SSH access.

3. Final Answer:

   Allows inbound TCP traffic on port 22 from any source -> Option A

4. Quick Check:

   Inbound TCP 22 allowed = SSH access [OK]

Hint: Inbound TCP 22 with Allow opens SSH [OK]

Common Mistakes:

• Confusing inbound with outbound
• Using UDP instead of TCP
• Misreading port number

4. You tried to connect to a Windows VM via RDP but the connection timed out. Which of these is the most likely cause based on NSG rules?

medium

A. NSG allows inbound TCP on port 3389

B. NSG allows inbound UDP on port 22

C. NSG blocks inbound TCP on port 3389

D. NSG allows outbound TCP on port 3389

Solution

1. Step 1: Understand RDP connection requirements

   RDP requires inbound TCP access on port 3389 to allow remote desktop connections.

2. Step 2: Identify blocking rule

   If NSG blocks inbound TCP on port 3389, the connection will time out because traffic is denied.

3. Final Answer:

   NSG blocks inbound TCP on port 3389 -> Option C

4. Quick Check:

   Blocked inbound TCP 3389 causes timeout [OK]

Hint: Blocked inbound TCP 3389 causes RDP timeout [OK]

Common Mistakes:

• Confusing inbound with outbound rules
• Using wrong port for RDP
• Assuming UDP is needed for RDP

5. You want to secure SSH access to your Linux VM in Azure so only your office IP (203.0.113.5) can connect. Which NSG rule configuration is best?

hard

A. Allow inbound TCP on port 22 from source 0.0.0.0/0

B. Allow inbound TCP on port 3389 from source 203.0.113.5/32

C. Allow inbound UDP on port 22 from source 203.0.113.5/32

D. Allow inbound TCP on port 22 from source 203.0.113.5/32

Solution

1. Step 1: Identify SSH port and protocol

   SSH uses TCP on port 22, so the rule must allow TCP on port 22.

2. Step 2: Restrict source IP to office IP

   To secure access, restrict source to the office IP with /32 mask for a single IP.

3. Step 3: Exclude incorrect options

   Allow inbound TCP on port 22 from source 0.0.0.0/0 allows all IPs (not secure), Allow inbound UDP on port 22 from source 203.0.113.5/32 uses UDP (wrong protocol), Allow inbound TCP on port 3389 from source 203.0.113.5/32 uses RDP port (wrong service).

4. Final Answer:

   Allow inbound TCP on port 22 from source 203.0.113.5/32 -> Option D

5. Quick Check:

   Restrict SSH TCP 22 to office IP [OK]

Hint: Restrict SSH port 22 TCP to your IP only [OK]

Common Mistakes:

• Allowing all IPs instead of specific IP
• Using UDP instead of TCP
• Opening wrong port for SSH