ORA-609 on the alert log with TNS lost contact on the client

I ran into this issue on a  2 node RAC 11.2.0.3 cluster   while accessing from the client PC.  here the scan listener was using a port 1590 while node listener was running on 1521 .   checking with the network team regarding firewall port opening for 1590 was verified. The information from network team regarding port 1521 was not clear  while troubleshooing over the weekend.. First of all looking the ORA-609  on the alert log was making the issue looks very confusing . I was seeng the request coming to the server on scan listener log .   It took a lot of hours  with no success .  so thought of giving a try to convert the node listener port  to also using 1590 port. which  did the trick .