App Service Inbound and Outbound Networking

Access restrictions in Azure App Service work like a network-level firewall that checks each incoming request before it reaches your application. You create a priority-ordered list of rules that either allow or block traffic based on IP addresses, IP ranges, or entire Azure Virtual Network subnets. When you add even one rule, Azure automatically adds an implicit "deny all" at the end, so only traffic you explicitly permit can reach your app. For Windows-based App Services, you can also set up dynamic IP restrictions through the web.config file, which adapts security based on how requests behave.