Connecting with the Oracle Instant Client 11g to Amazon Cloud Web Services (amazonaws.com) can result in the next error:
ORA-28547: connection to server failed, probable Oracle Net admin error
I found that while pinging the host, it was not able to resolve it, but connecting with SQL Developer (4.1.0.17) was possible! Strange…
I downloaded the Oracle Instant Client 12c (12.1.0.2) and that works. It seems the Oracle Instant Client 11g (11.2.0.4) is not able to connect to Amazon Web Services…
Happy connecting!