Neutron enables users to build routers that provide connectivity between the networks created by users and external networks. In a reference implementation, the Neutron L3 agent provides IP routing and network address translation for virtual machine instances within a cloud by utilizing network namespaces to provide isolated routing instances. By creating networks and attaching them to routers, users can expose connected virtual machine instances and their applications to the Internet and other remote networks.
Prior to the Juno release of OpenStack, users were limited to building standalone routers that acted as single points of failure in the network stack. Since the advent of distributed virtual routers in Juno and beyond, standalone routers are now referred to as legacy routers.
In previous chapters, we discovered the difference between provider and tenant networks and demonstrated the process of booting an instance and connecting it...