Application Gateway

Azure Application Gateway gives you application-level routing and load balancing services that let you build a scalable and highly-available web front end in Azure.

You control the size of the gateway and scale your deployment based on your needs.

It will comes under Layer 7(Application) in OSI model. We will called it as path based routing.

• Basically, Azure supports two types of load balancers at OSI layer which is layer 4 and layer 7.
• Standard and Basic load balancer will comes under layer 4 (Transport) where as Application gateway will comes under Layer 7 (Application).
• Basic and standard load balancer is only used as a proxy to send the traffic at the backend where as application gateway will use the path based routing.

For e.g.:

abc.xyz/home

abc.xyz/movies

abc.xyz/songs

Minimum instance count: Additional reserved capacity which is always maintained irrespective of traffic. 0 signifies purely autoscaling Application Gateway with no additional reserved capacity while still maintaining high availability of the service.

Steps to create application gateway:

1. We need to create one dedicated subnet.
2. Require one public ip address
3. Add Backendpool –Add VM’s (We can add IP address, VM’s, VMSS, APPServices)
4. Create Routing rules. — Add Listener and backend targets
5. Click on Create

Post configurations:

Configure path based routing

Below are the screenshots for references.