The file called sqlnet.log shows all failed attempts to connect to remote databases. Oracle does not clean up this file and will append to it forever, so you may want to go to the log_directory_client directory and delete the sqlnet.log file.
View the code below to see a sample of the contents of a sqlnet.log file.
(The error indicates that the remote listener process is not running.)
We will investigate the log files in detail in a later module,
Oracle Net Client Configuration
Legacy Information regarding Oracle 7 and Oracle 8
Oracle Net (which is Oracle's network interface), was formerly known as Net8 when used in Oracle8, and SQL*Net when used with Oracle7 and previous versions of Oracle.
You can use Oracle Net over a wide variety of network protocols, although TCP/IP is by far the most common protocol today.
The sqlnet.ora file on a client machine contains parameters that govern the behavior of the client. The attributes that can be modified fall into five categories: