Neutron routers are a core component of networking in OpenStack and provide users the flexibility to design the network to best suit their application. The use of floating IPs allows users to quickly and programmatically provide direct connectivity to applications while preserving limited IPv4 address space through the use of network address translation.
Standalone routers are easy to implement but are a single point of failure in any network design. In the event of an L3 agent failure, all routers scheduled to the agent may become unavailable or unreliable. In the next chapter, we will discuss how Neutron implements highly available routers using the Virtual Router Redundancy Protocol, or VRRP, to solve many of the shortcomings of legacy standalone routers.
