Before Juno, when we deploy Openstack in production, there always is a painful point about L3 Agent: High availability and performance bottleneck. Now Juno comes with new Neutron features to provide HA L3-agent and Distributed Virtual Router (DVR).
DVR distributes East-West traffic via virtual routers running on compute nodes. Also virtual routers on compute nodes handle North-South floating IP traffic locally for VM running on the same node. However if floating IP is not in use, VM originated external SNAT traffic is still handled centrally by virtual router in controller/network node.
HA L3 Agent provides virtual router HA by VRRP. A virtual gateway IP is always available from one of controller/network node.
Let’s take a look how they work in details
Steps to enable DVR:
DVR currently only supports tunnel overlays (VxLAN or GRE) with l2population enabled, VLAN as overlay is not supported yet.
View original post 2,167 more words