Comment 2 for bug 1285067

Yes, there is an issue with server/port interaction on stack update.

I think what is happening is the following.
On update, if server is replaced then the new server is assigned a new port by neutron, but heat doesn't know what the new port UUID is, and assumes the old port UUID is still valid (even though it was deleted as a side-effect of deleting the nova server).

With luck, all that is required is for the server resource to detach any ports that are specified by networks.port before deleting the server.

Its possible that the fix for this will also fix bug 1196479