Granting and denying access to the a database is crucial for a secure network environment. You can configure access control through a firewall or on the database. For firewall support, you can configure Oracle Connection Manager to function as a firewall, whereby it grants or denies clients access to a particular database service or a computer based on a set of filtering rules. For the database, you can configure access control parameters in the file to specify that clients using a particular protocol are allowed or denied access