Introduction

We saw that the Network provides tenants with an isolated Layer 2 domain in which virtual machines can communicate with one another. However, in real-life deployment, you will find many scenarios where two or more networks need to communicate with each other. This connectivity between virtual machines across two different Layer 2 Networks is accomplished using a Router. The Router object in OpenStack provides VMs with Layer 3-based IP Routing services.

The OpenStack default Router runs on the Network nodes in OpenStack. In order to implement the recipes, you will need an OpenStack setup as described in the following figure:

This setup has two compute nodes and one node for the controller and networking services. For this chapter, you can also use a setup with just one compute node. Compared to the earlier chapters, this setup has an additional Network called External Network. This Network allows the Network node to carry traffic from the VM instances to an external Network and...