How to control access to the database and understand validnode checking

You can configure the sqlnet.ora file to allow and deny access to the database
via the validnode checking parmeters.


TCP.VALIDNODE_CHECKING
Use to specify whether to screen access to the database.Value is either YES or ON

TCP.EXCLUDED_NODES
Use to specify which clients using the TCP/IP protocol are denied access to the database.
Hostname and ipaddress can be used

TCP.INVITED_NODES
Use to specify which clients using the TCP/IP protocol are allowed access to the database.
Hostname and ipadddress can be used.


Example sqlnet.ora file (set where database is running)

TCP.VALIDNODE_CHECKING = YES
TCP.EXCLUDED_NODES= (138.3.33.33)
TCP.INVITED_NODES=(138.4.44.44, hammer)