In this chapter, we have covered several aspects behind network extensibility in OpenStack by the means of plugins. We have explored the power of ML2 support in the latest releases of OpenStack and demonstrated how to write a custom mechanism driver as an extension to the core plugin. The topic of high network availability was left behind prior to the Havana release; later releases have empowered the Neutron project by kicking off built-in solutions in the OpenStack network service. We have covered routing redundancy using VRRP and routing distribution based on the DVR approach. While both HA network designs have drastically boosted the network architecture in an extended OpenStack environment, each solution might have its own limitations. Hence, as a cloud operator, taking architectural decisions on choosing which solution might fit depends roughly on the infrastructure...





















































