AZ-104 Certification Notes

Chapter 11.2 - Routing Rules

Application Gateway - Routing Rules

Listeners A listener "listens" on a specified port and IP address for traffic that uses a specified protocol. If the listener criteria are met, the application gateway will apply this routing rule.

There are 2 types of listeners:

1. Basic - Forward all requests for any domain to backend pools
2. Multi-site - Forward requests to different backend pools based on host header and host name

• Requests are matched according to the order of the rules and the type of listener
  • Add your basic listeners last otherwise it will capture all requests

Backend targets Chooses where a route should go either Backend Pool or Redirection

HTTP Settings To create a rule for Backend Pool you need to create HTTP Setting. This allows to define how we want to handle cookies, connection draining, port request time out and more..

Backend Port The port where the back-end servers listen to incoming traffic.

Cookie-based affinity Use cookies to keep a user session on the same server.

Connection draining Gracefully remove backend pool members during planned service updates.

Request Timeouts The number of seconds that the application gateway will wait to receive a response from the backend pool before it returns a "connection timed out" error message.

Override backend path Allows you to override the path in the URL so that the requests for a specific path can be routed to another path.

Override Hostname Multi-tenant services like App service or API management rely on a specific host header or SNI extension to resolve to the correct endpoint. Change these settings to overwrite the incoming HTTP host header.

Practice Quiz

• Which Routing Rule allows you to override the path in the URL so that the requests for a specific path can be routed to another path?

  • Request timeouts
  • Backend Port
  • Override Hostname
  • Override backend path

• Which Routing Rule uses cookies to keep a user session on the same server?

  • Backend Port
  • Cookie-based affinity
  • Override backend path
  • Request timeouts

• What is connection draining?

  • Gracefully removes backend pool members during planned service updates.

• What is Override Hostname?

  • Multi-tenant services like App service or API management reply on a specific host header or SNI extension to resolve to the correct endpoint.