In case of 2 node 3 node 4 node and n node RAC how does oracle decide about where to put scan listeners i.e. for 3 node does it have 1 in each node , in 4 node if there are 3 scan listeners and IP addresses how does oracle know which node to put the 3 because I guess 1 node will be left without scan IP , then how does that node deal with SCAN IP and Listener fundas in 11g.