Oracle Listener Block IPs

Reference: http://www.dba-oracle.com/t_blocking_listener_ip_addresses.htm

$ cat /usr2/app/oracle/product/11.2.0.3/network/admin/sqlnet.ora

#
NAMES.DIRECTORY_PATH= (LDAP, TNSNAMES, ONAMES, HOSTNAME)

tcp.validnode_checking = yes
tcp.invited_nodes = (localhost,streaming)