Azure Application Gateway

• A web traffic load balancer that enables you to manage traffic to your web applications
• Application Gateway can make routing decisions based on additional attributes of an HTTP request, for example URI path or host headers
• A managed load balancing service that can perform layer-7 routing and SSL termination
• Provides
  • Application delivery controller (ADC) as a service
  • Layer 7 load-balancing capabilities
  • SSL termination
  • Web application firewall (WAF)
• Application layer (OSI layer 7) load balancing
• Azure Application Gateway can do URL-based routing and more

Application Gateway load balances HTTP(S) and WebSocket requests to route traffic to backend pool servers. The backend can be public or private endpoints, virtual machines, virtual machine scale sets, app services, or Kubernetes clusters. Traffic can be routed based on attributes of an HTTP request, such as a host name and URI path.

Links:

• https://docs.microsoft.com/en-us/azure/application-gateway/
• https://docs.microsoft.com/en-us/azure/application-gateway/features

Azure API Management

API Gateway

• An API gateway is an API management tool that sits between a client and a collection of backend services
• An API gateway acts as a reverse proxy to accept all application programming interface (API) calls, aggregate the various services required to fulfill them, and return the appropriate result

API Gateway service in Azure

• Azure API Management (APIM)
• APIM = API Gateway + xyz (where xyz -> Developer portal, publisher portal, policy etc.)
• APIM provides a powerful policy framework to manipulate requests both inbound and outbound, along with advanced features rate limiting and conditional caching
• API Management is a turnkey solution for publishing APIs to external and internal customers
• It provides features that are useful for managing a public-facing API, including rate limiting, IP restrictions, and authentication using Azure Active Directory or other identity providers

APIM doesn’t perform any load balancing, so it should be used in conjunction with a load balancer such as Application Gateway or a reverse proxy

VPN Gateway

• A VPN gateway is a specific type of virtual network gateway that is used to send encrypted traffic between an Azure virtual network and an on-premises location over the public Internet
• Details: VPN gateway in Azure VNet