OpenStack was designed with multitenancy 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. It is able to isolate many of those 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 interface devices. When using the open source reference plugins and drivers, every network, router, and load balancer that is created by a user is represented by a network namespace. When network namespaces are enabled, Neutron is able to provide isolated DHCP and routing services to each network. These services allow users to create overlapping networks with other users in other projects and even other networks in the same project.