Red Hat OpenStack Administration I: Core Operations for Domain Operators
In this chapter, you learned:
OVN is the default SDN solution for Red Hat OpenStack Platform. It replaces the OVS ML2 driver and the neutron agent with the OVN ML2 driver. The OVS ML2 driver had some limitations and complications. The OVN ML2 driver addresses those problems.
The OVN database is installed in a central location. It can be installed on a physical node, a virtual node, or on a cluster. The choice of location depends on various factors, including the size of the cloud infrastructure, the geographic dispersion of the cloud, the volume of traffic, and the performance required. The hypervisors must run Open vSwitch for OVN to work.
OVN implements DHCP and OpenStack security groups. The OVN gateway links the overlay network to the physical network. The overall OVN architecture and configuration simplifies OpenStack networking.
Self-service, or tenant, networks are a common network type in many OpenStack installations. They only contain virtual components. Only instances within the project can use tenant networks.
Provider, or data center, networks are the most common production network type at RHOSP installations. They are defined using the existing data center networks and VLANs. Provider networks are shared and can be configured to be used by any project's instances.
Tenant instances which require external access must be created on a network with a router providing access to the public network. A floating IP address must be added to instance as the fixed IP address assigned at creation cannot be used on the public network.
