Database Software

Hi

I have set remote_listener for my db’s to scan-cluster.domain:port number ( and scan works fine )
but we not using the scan address yet,this is because most of my clients are still using old client version and therefore in their tnsnames or jdbc connections they have the node1-vip / node2-vip address. Is this is a problem?
I ask because I occasionally see “ORA-12514, TNS:listener does not currently know of service requested in connect descriptor” in the application log file ( this only happens only when 1 node of the rac is down! ) but why ?my app is using jdbc, I wondered if I need to use the cluster ip in the jdbc connection or maybe change remote listener to second node of rac instead of the scan address.

Thanks