Explanation
https://docs.microsoft.com/en-us/azure/aks/virtual-nodes

Topic 4, HABInsurance
Case Study
An insurance company, HABInsurance, operates in three states and provides home, auto, and boat insurance.
Besides the head office, HABInsurance has three regional offices.
Current environment
General
An insurance company, HABInsurance, operates in three states and provides home, auto, and boat insurance.
Besides the head office, HABInsurance has three regional offices.
Technology assessment
The company has two Active Directory forests: main.habinsurance.com and region.habinsurance.com.
HABInsurance's primary internal system is Insurance Processing System (IPS). It is an ASP.Net/C# application running on IIS/Windows Servers hosted in a data center. IPS has three tiers: web, business logic API, and a datastore on a back end. The company uses Microsoft SQL Server and MongoDB for the backend.
The system has two parts: Customer data and Insurance forms and documents. Customer data is stored in Microsoft SQL Server and Insurance forms and documents-in MongoDB. The company also has 10 TB of Human Resources (HR) data stored on NAS at the head office location. Requirements General HABInsurance plans to migrate its workloads to Azure. They purchased an Azure subscription. Changes During a transition period, HABInsurance wants to create a hybrid identity model along with a Microsoft Office 365 deployment. The company intends to sync its AD forests to Azure AD and benefit from Azure AD administrative units functionality.
HABInsurance needs to migrate the current IPSCustomers SQL database to a new fully managed SQL database in Azure that would be budget-oriented, balanced with scalable compute and storage options. The management team expects the Azure database service to scale the database resources dynamically with minimal downtime. The technical team proposes implementing a DTU-based purchasing model for the new database.
HABInsurance wants to migrate Insurance forms and documents to Azure database service. HABInsurance plans to move IPS first two tiers to Azure without any modifications. The technology team discusses the possibility of running IPS tiers on a set of virtual machines instances. The number of instances should be adjusted automatically based on the CPU utilization. An SLA of99.95% must be guaranteed for the compute infrastructure.
The company needs to move HR data to Azure File shares.
In their new Azure ecosystem, HABInsurance plans to use internal and third-party applications. The company considers adding user consent for data access to the registered applications Later, the technology team contemplates adding a customer self-service portal to IPS and deploying a new IPS to multi-region ASK. But the management team is worried about performance and availability of the multi-region AKS deployments during regional outages.

Explanation
Much like the most popular Kubernetes Ingress Controllers, the Application Gateway Ingress Controller provides several features, leveraging Azure's native Application Gateway L7 load balancer. To name a few:
URL routing
Cookie-based affinity
Secure Sockets Layer (SSL) termination
End-to-end SSL
Support for public, private, and hybrid web sites
Integrated support of Azure web application firewall
Application Gateway redirection support isn't limited to HTTP to HTTPS redirection alone. This is a generic redirection mechanism, so you can redirect from and to any port you define using rules. It also supports redirection to an external site as well.
Reference:
https://docs.microsoft.com/en-us/azure/application-gateway/features

Explanation