Hi,

Thanks for your reply, they are really good posts, I guess I have answer now. It's true that FIP namespace is used for proxy ARP, but in old way(centralized router), there is also interface in qrouter namespace for that, so why not keep the old way? the answer is saving the floating IP. If we use the old way, every DVR router which handle floating IP in same compute node will have an extra external IP from floating IP range to do ARP proxy point, it will waste floating IPs. Now there is FIP namespace used to provide unified ARP proxy point, no matter how many routers in same compute node, they are all connected to FIP namespace, it only cost one floating IP to do ARP proxy.