OpenStack was designed with multi-tenancy in mind, and provides users with the ability to create and manage their own compute and network resources. Neutron supports each tenant having multiple private networks, routers, firewalls, load balancers, and other networking resources, and is able to isolate many of these objects through the use of network namespaces.
A network namespace is defined as a logical copy of the network stack with its own routes, firewall rules, and network interfaces. When using the open source reference plugins and drivers, every DHCP server, router, and load balancer that is created by a user is implemented in a network namespace. By using network namespaces, Neutron is able to provide isolated DHCP and routing services to each network, allowing users to create overlapping networks with other users in other projects and even other networks...
