Hi car1, In the link: https://docs.google.com/document/d/1jCmraZGirmXq5V1MtRqhjdZCbUfiwBhRkUjDXGt5QUQ/edit, there is some words like " When the node is being scheduled to host the SNAT, a new namespace and internal IP address will be assigned to host the SNAT service. Any nova instance VM that is connected to the router will have this new SNAT IP as its external gateway address. " Can nova VM see this secondary IP? I think that even in the node hosting SNAT, IR still exists. So VM at this node will also see IP of the IR interface, and send packet to IR first, next the IR will redirect the traffic to SNAT in the same node (but in different namespace). Is that right? -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.openstack.org/pipermail/openstack-dev/attachments/20140613/b0ecc86a/attachment.html>