Why SSH and RDP access in Azure? - Purpose & Use Cases

The Big Idea

Discover how simple remote access can save you hours of frustration and keep your cloud servers secure!

The Scenario

Imagine you need to connect to a remote computer to fix a problem or install software. You try to remember the IP address, username, and password, then open a command prompt or remote desktop app each time. Sometimes you mistype the password or lose connection, and you have to start over.

The Problem

Manually connecting to remote machines is slow and frustrating. You risk typing errors, security issues from sharing passwords, and inconsistent access methods. It's like trying to open many locked doors with different keys, without a clear system.

The Solution

SSH and RDP access provide a secure, standardized way to connect remotely. SSH uses encrypted commands for Linux machines, while RDP offers a graphical interface for Windows. Both let you connect easily, safely, and reliably, saving time and avoiding mistakes.

Before vs After

✗ Before

telnet 192.168.1.10
Enter username and password manually

✓ After

ssh azureuser@192.168.1.10
Use saved keys for passwordless login

What It Enables

With SSH and RDP, you can securely manage remote servers anytime, anywhere, as if you were sitting right in front of them.

Real Life Example

A cloud engineer uses SSH to quickly update a Linux server in Azure without leaving their desk, or uses RDP to troubleshoot a Windows VM's desktop environment remotely.

Key Takeaways

Manual remote access is slow and error-prone.

SSH and RDP provide secure, easy connections.

They enable efficient remote management of cloud servers.

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