The Dell EMC Ready Architecture for Red Hat OpenStack Platform version 16.1 provides the ability to enable Distributed Virtual Routing (DVR) on all all the compute nodes in the solution.
Distributed Virtual Routing (DVR) offers an alternative routing design to the centralized routing model. It intends to isolate the failure domain of the Controller node and optimize network traffic by deploying the L3 agent and schedule routers on every Compute node. By eliminating a centralized layer 3 agent, the routing that was performed by single node (Primary controller), is now distributed across the compute nodes using the local L3 agent. DVR follows the below routing flow rules:
- East-West traffic is routed directly on the Compute nodes in a distributed fashion.
- North-South traffic with floating IP is distributed and routed on the Compute nodes. This traffic requires the external network connects to each Compute node.
- North-South traffic without floating IP allocates and still needs a dedicated Controller node.
- The L3 agent on the Controller node is configured with a new dvr_snat mode so that the node serves only SNAT traffic.
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The Neutron metadata agent distributes and deploys on all Compute nodes. The metadata proxy service hosts all the distributed routers.