Sqlnet.ora is a text file that provides SQL*Net with basic configuration details like tracing options, default domain, encryption, etc. This file can be found in the ORACLE HOME\NETWORK\ADMIN directory.
 Sample sqlnet.ora files
NAMES.DIRECTORY_PATH= (LDAP, TNSNAMES, HOSTNAME) NAMES.DEFAULT_DOMAIN = WORLD TRACE_LEVEL_CLIENT = OFF SQLNET.EXPIRE_TIME = 30
automatic_ipc = ON # Set to OFF for PC's trace_level_client = OFF # Set to 16 if tracing is required sqlnet.expire_time = 0 # Idle time in minutes sqlnet.authentication_services = (ALL) names.directory_lookup = (TNSNAMES,ONAMES) names.default_domain = world name.default_zone = world
Some of the parameters that can be set in sqlnet.ora:
The value of this parameter is appended to the net service name if the net service name doesn't already have a domain.
Enables dead connection detection, that is, after the specified time (in minutes) the server checks if the client is still connected. If not, the server process exits. This parameter must be set on the server.
Enables tracing if not set to off (or 0, which is the default). Possible values: USER (4), ADMIN (10) and SUPPORT (16).
Specifies the name of the (client) trace file. The default is sqlnet.trc.
Specifies the destination directory in which the trace file goes. The default is the current directory in which the executable is started.
When automatic_ipc=on, SQL*Net will bypass the network layer and make direct local connections to the database. This is useful on database servers.
The default is NO (turn signal handling on). By setting BEQUEATH_DETACH=YES, Oracle turns off its own signal handlers and pass all child processes over to the UNIX init process (pid = 1). The init process will take over responsibility to checks for "defunct" child processes and terminate them.
Instead of setting this parameter in the sqlnet.ora file, consider setting it as an environment variable before starting applications that use signal handlers that could interfere with SQL*Net. Example:
Time in seconds after which a connection attempt will be timed out. After timeout, the client will try to connect to the next host on the ADDRESS_LIST. This facilitates quick fail-over in case a system/node is down. This parameter should typically be set to +- 3 seconds. If not set, the client connection will block for the default TCP connect timeout duration.
In 11.1 and above this parameter sets the timeout for establishing a TCP connection.