I see. DNS is so critical nobody company can survive without a good DNS infrastructure. Using IPs instead of hostnames offers a little performance advantage. The DBA has to remember to change them if the IPs change. Hostnames are normally more stable than IPs.
Do you still remember what JDBC thin driver has the redirection problem? I want to know if we're using it. We have a large number of applications using all kinds of drivers.
Your solution on your blog is what the original poster already did. Basically, what you did is "设置rac每个节点的系统参数LOCAL_LISTENER". But read message #1. He already did that.