How to solve Firewall Problems when using Oracle
Question / Problem
If CRX is configured to use an Oracle database, and when using a firewall, it is possible that the repository 'hangs' after some time.
Answer / Resolution
This problem may be caused by a firewall that drops idle TCP connections.
Usually CRX automatically re-connects to the database when the connection is broken, but this mechanism does not work efficiently with the Oracle JDBC driver, because the default read timeout of the Oracle driver is too long. That means the firewall timeout for idle-connections may block the connection.
If you run into this problem, enable Oracle Net DCD by setting SQLNET.EXPIRE_TIME=1 in the sqlnet.ora file on the server-side.