Define the Networking Managers in OpenStack Cloud

Flat Network Manager: This connects all virtual machines to a single network, using the same subnet and bridge that the administrator set up. As a result, all VMs are linked to the same network and are recognized to have Flat Network Manager.

Flat DHCP Network Manager: Similar to the above, except the IP addresses for the virtual machines are assigned using DHCP (Dynamic Host Configuration Protocol).

VLAN: Unlike a single network, VLAN allows for a more secure and distinct network for virtual machines. It has a physical switch that allows each tenant to have their own virtual network, IP range, and bridge. This is, without a doubt, the best option for a multi-tenant/project setting.

OpenStack Networking allows you to create and manage network objects, such as networks, subnets, and ports, which other OpenStack services can use. Plug-ins can be implemented to accommodate different networking equipment and software, providing flexibility to OpenStack architecture and deployment.

The Networking service, code-named neutron, provides an API that lets you define network connectivity and addressing in the cloud.