Neutron routers are a core component of networking in OpenStack and provide tenants with the flexibility to design a network best suiting their application. The use of floating IPs allows tenants to quickly and programmatically provide direct connectivity to applications while preserving limited IPv4 address space through the use of network address translation.
Standalone routers may be easy to implement, but they 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 Virtual Router Redundancy Protocol, or VRRP, to solve many of the shortcomings of standalone routers.