Learning OpenStack Networking - Third Edition

Plumbing it up

When a distributed virtual router is connected to a subnet using the OpenStack router add subnet or add port commands, the router is scheduled to all nodes hosting ports on the subnet and running the Open vSwitch agent, including any controller or network node hosting DHCP or load balancer namespaces and any compute node hosting virtual machine instances in the subnet. The L3 agents are responsible for creating the respective qrouter network namespace on each node, and the Open vSwitch agent connects the router interfaces to the bridges and configures the appropriate flows.