Automating Microsoft Azure Infrastructure Services

Chapter 4. Virtual Machine Networking

Automating the Network

In Chapter 3 we got our feet wet with creating and updating virtual machines, and as part of that we briefly covered modifying network endpoints by adding and removing them through PowerShell. In this chapter we will dive deeper and learn how to manage more-advanced scenarios such as configuring the load balancer, TCP and HTTP health probes, reserved IP addresses, and of course network security using access control lists (ACLs). We will discuss deploying a virtual machine into a virtual network in Chapter 6.

Handling External Traffic

With Microsoft Azure Virtual Machines, you have a lot of control over how network traffic from the outside world is managed. This control manifests itself in an entity that you can manage through the management portal and is surfaced through the API and ultimately to tools such as PowerShell; that entity is the endpoint.

What exactly is an endpoint? An endpoint is an inbound rule associated with a virtual machine that allows you to tell Microsoft Azure what do with incoming traffic. You can set many properties of the endpoint for different behaviors.

Port Forwarding

Port forwarding is a simple but powerful concept. An endpoint listens on a public port and forwards traffic to an internal port. The internal and public ports can be the same or different.

For instance, your cloud service might contain two virtual machines, and each virtual machine is listening on port 3389 for remote desktop. How do ...