What is Azure Bastion and Why is it Recommended?

Azure Bastion is a fully managed Azure PaaS service that provides secure RDP and SSH connectivity to Azure virtual machines without requiring those VMs to have public IP addresses. Connections are made through TLS, including connectivity from the Azure portal, and Bastion is deployed into the virtual network.

This addresses a common architectural problem.

Traditionally, administrators might expose:

Internet
   ↓
Public IP
   ↓
VM
   ↓
RDP 3389 / SSH 22

That creates an externally reachable management surface.

With Bastion:

Administrator
      ↓
Azure Bastion
      ↓
Private IP
      ↓
Azure VM

The VM does not need a public IP for the Bastion connection.

Why is this more secure?

RDP and SSH are extremely sensitive administrative protocols.

Exposing them directly to the Internet increases the attack surface and can expose systems to:

• Port scanning
• Credential attacks
• Exploitation attempts
• Misconfiguration
• Unintended exposure

Azure Bastion provides RDP/SSH connectivity over TLS on port 443 and helps protect VMs from external port scanning.

Bastion is a jump-host architecture

Conceptually:

                  INTERNET
                     │
                     │ HTTPS/TLS
                     ▼
              ┌───────────────┐
              │ Azure Bastion │
              └───────┬───────┘
                      │
              Azure Virtual Network
                      │
        ┌─────────────┼─────────────┐
        ▼             ▼             ▼
      VM 1           VM 2          VM 3
    Private IP     Private IP    Private IP

This is essentially a managed bastion/jump-host pattern without requiring you to operate your own jump server.

Operational advantages

Azure Bastion is managed by Microsoft, reducing the need to maintain a dedicated jump VM.

Depending on SKU, capabilities include features such as native-client connectivity, scaling, shareable links, IP-based connections, custom ports, file transfer, and—at Premium—session recording and private-only deployment.

Is Bastion a replacement for all network security?

No.

This is an important expert distinction.

Bastion provides secure administrative access to VMs.

It does not replace:

• Network Security Groups
• Azure Firewall
• Identity controls
• Microsoft Defender for Cloud
• Privileged Identity Management
• Endpoint security
• Network segmentation
• Monitoring and logging

A mature architecture combines these controls.

For example:

Microsoft Entra ID
        ↓
Conditional Access / MFA
        ↓
Azure Bastion
        ↓
NSG / Network Controls
        ↓
Private VM
        ↓
Workload Security
        ↓
Monitoring + Defender