Blocking Oracle user access by IP Address.

We are able to block clients based on their IP address or host name using oracle sqlnet.ora file which exist in  D:\IN\Oracle\product\10.2.0\db_1\network\ADMIN this path.

1. Go to D:\IN\Oracle\product\10.2.0\db_1\network\ADMIN and open  sqlnet.ora file.

2. Insert the following lines.

# authentication, they will not be able to connect to the database on NT.

SQLNET.AUTHENTICATION_SERVICES = (NTS)

tcp.validnode_checking = yes             
                          
#This turns on the hostname/IP checking for your listeners. After this you can select list of host/IP # which you are allow to database connection.
 
tcp.invited_nodes = (localhost, 10.11.201.150, 10.11.201.200)

# This the list of host name or IP Address.

3. Now restart your listener.


Now you can try to connect your database from another IP Like 10.11.201.204 you can get error message.