Azure VPN Gateway: A Comprehensive Guide
Why is Azure VPN Gateway Important?
Azure VPN Gateway allows you to create secure and encrypted connections between your on-premises network and your Azure virtual network (VNet), or between two Azure VNets. This is crucial for Hybrid Cloud scenarios, disaster recovery, and secure remote access.
What is Azure VPN Gateway?
Azure VPN Gateway is a virtual network gateway service. It enables you to create secure connections to your Azure Virtual Network from another location. A VPN gateway is a specific type of virtual network gateway used for sending encrypted traffic between an Azure Virtual Network and an on-premises location over the public Internet. You can also use VPN Gateway to send encrypted traffic between Azure Virtual Networks over the Microsoft network.
How Azure VPN Gateway Works:
The VPN Gateway uses various protocols to establish secure connections. Common protocols include:
- IPsec/IKE (Policy Based or Route Based): Used for site-to-site and VNet-to-VNet connections. Establishes an encrypted tunnel.
- IKEv2: Often used for point-to-site VPN connections (connecting individual devices).
- OpenVPN: An open-source VPN protocol often used for point-to-site connections, offering strong security.
The process typically involves:
1. Creating a VPN Gateway in Azure (specifying the gateway type, VPN type, SKU, and generation).
2. Creating a Local Network Gateway in Azure (representing your on-premises network's VPN device).
3. Configuring your on-premises VPN device with the Azure VPN Gateway settings.
4. Establishing a secure tunnel using a shared key or certificates.
There are several types of Gateways:
- Route-Based: More flexible, supports dynamic routing protocols (BGP), and is generally preferred.
- Policy-Based: Uses static routing policies and is less flexible. *(Less commonly used, but be aware of it)*
Important Concepts:
- Gateway Subnet: A dedicated subnet within your VNet for the VPN Gateway.
- Connection: The logical connection between the VPN Gateway and another gateway (Local Network Gateway or another VPN Gateway).
- Local Network Gateway: Represents your on-premises VPN device or another Azure VPN Gateway.
- SKUs: Different tiers of VPN Gateways offering varying performance, features, and costs (Basic, VpnGw1, VpnGw2, VpnGw3, VpnGw4, VpnGw5). Choosing the right SKU depending on bandwidth requirements and number of connections is essential.
- BGP (Border Gateway Protocol): A dynamic routing protocol that can be used to exchange routing information between your on-premises network and Azure.
Exam Tips: Answering Questions on Azure VPN Gateway
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Understand the Scenarios: Focus on when to use VPN Gateway versus other connectivity options like ExpressRoute. VPN Gateway is best for lower bandwidth requirements, proof-of-concept scenarios, or when ExpressRoute isn't feasible.
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Know the Gateway Types and Protocols: Distinguish between Route-Based and Policy-Based gateways. Understand the purpose and use cases for protocols like IPsec/IKE, IKEv2, and OpenVPN. Route-based generally the correct answer unless policy based is specifically asked for.
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Be Familiar with SKUs: Learn the different VPN Gateway SKUs and their capabilities (bandwidth, connections, features). Recognize which SKU is appropriate for various workload requirements.
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Understand Local Network Gateway: Know that it is the *
representation of your on-premises* VPN device inside of Azure.
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Troubleshooting: Be familiar with the basic troubleshooting steps like checking the VPN Gateway status, verifying the shared key, and using tools like Azure Network Watcher to diagnose connectivity issues.
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Hybrid Cloud Scenario: Questions often involve hybrid cloud setups needing secure connectivity of network resources. Understand how VPN Gateway address those situations.
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Always encrypt sensitive data: when transferring over the public Internet using VPN, there is always encryption. This is vital for HIPAA, PCI and other regulations.