Why Hybrid Connectivity Matters
Most organizations don’t move everything to the cloud at once. They need to connect on-premises networks to Azure securely. Azure provides two main options: VPN Gateway and ExpressRoute.
VPN Gateway
A virtual network gateway that provides encrypted tunnels between Azure VNets and on-premises networks (or even between VNets).
Key Features:
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Uses IPsec/IKE VPN protocols.
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Can be used for Site-to-Site (S2S), Point-to-Site (P2S), or VNet-to-VNet connections.
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Runs as a managed service inside a dedicated subnet called the GatewaySubnet.
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Bandwidth depends on SKU (Basic, VpnGw1, VpnGw2, etc.).
ExpressRoute
A private, dedicated connection between your on-premises datacenter and Azure.
Key Features:
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Does not use the public internet (more secure & reliable).
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Provides high bandwidth (up to 10–100 Gbps).
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Lower latency compared to VPN.
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Requires a connectivity provider (ISP or partner).
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Supports hybrid scenarios where sensitive data must not traverse the public internet.
VPN vs ExpressRoute
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VPN Gateway:
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Uses internet.
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Encrypted tunnel.
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Lower bandwidth (good for small/medium workloads).
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ExpressRoute:
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Private dedicated circuit.
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High bandwidth, low latency.
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Better for enterprises with mission-critical apps.
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Exam trick: If you see “dedicated private circuit”, the answer is ExpressRoute. If you see “encrypted over internet”, the answer is VPN Gateway.
Confusion Buster 🚨
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Point-to-Site (P2S) vs Site-to-Site (S2S)
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P2S = individual client (e.g., remote worker’s laptop → Azure).
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S2S = entire on-premises network connected to Azure VNet.
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Exam trap: If question mentions “remote developer connecting securely,” → Point-to-Site VPN. If it says “connect company HQ to Azure,” → Site-to-Site VPN.
Simple Example
A company has:
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HQ datacenter → connected to Azure via Site-to-Site VPN Gateway.
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Remote developers → connect to Azure via Point-to-Site VPN.
Later, the company upgrades to ExpressRoute for better speed and reliability of their SAP workloads.
Exam Tip
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VPN Gateway requires a GatewaySubnet.
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ExpressRoute requires a service provider.
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Always pick ExpressRoute for high bandwidth, low latency, private connections.
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Pick VPN for fast setup and lower cost.
What to Expect in the Exam
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Direct Q: “Which service provides a dedicated private circuit to Azure?” → ExpressRoute.
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Scenario: “Remote developers need secure access to Azure from home.” → Point-to-Site VPN.
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Scenario: “Company wants to connect on-premises HQ to Azure over the internet using encryption.” → Site-to-Site VPN.
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Trick Q: “VPN Gateway provides private dedicated bandwidth.” (False, that’s ExpressRoute).