相对与单节点的oracle ，11gr2 rac中，listener是配置在GRID_HOME，而不是ORACLE_HOME,所以我们要修改的sqlnet.ora文件是在GI_HOME/network/admin目录下的而非ORACLE_HOME/network/admin 目录。
实验环境：
数据库版本 11.2.0.1.0
rac1 10.250.7.225
rac2 10.250.7.249 vip 10.250.7.112
rac3 10.250.7.241
1 最初的配置，tcp.invited_nodes只包含rac1，rac2两个节点的ip,不包含rac3的ip
grid@rac1:/opt/11202/11.2.0/grid/network/admin>vim sqlnet.ora
NAMES.DIRECTORY_PATH= (TNSNAMES, EZCONNECT)
tcp.validnode_checking=yes
#允许访问的ip
tcp.invited_nodes =(10.250.7.225,10.250.7.249)
ADR_BASE = /opt/rac/grid
grid@rac2:/opt/11202/11.2.0/grid/network/admin>vim sqlnet.ora
NAMES.DIRECTORY_PATH= (TNSNAMES, EZCONNECT)
tcp.validnode_checking=yes
#允许访问的ip
tcp.invited_nodes =(10.250.7.249,10.250.7.225)
ADR_BASE = /opt/rac/grid
2 在rac3 上进行测试tnsping rac1 rac2
oracle@rac3:/opt/oracle/11.2.0/alifpre/network/admin>tnsping rac1
TNS Ping Utility for Linux: Version 11.2.0.1.0 - Production on 15-DEC-2011 16:19:46
Copyright (c) 1997, 2009, Oracle. All rights reserved.
Used parameter files:
/opt/oracle/11.2.0/alifpre/network/admin/sqlnet.ora
Used TNSNAMES adapter to resolve the alias
Attempting to contact (DESCRIPTION = (ADDRESS_LIST = (ADDRESS = (PROTOCOL = TCP)(HOST = 10.250.7.225)(PORT = 1521))) (CONNECT_DATA = (SID = rac1)))
TNS-12547: TNS:lost contact
oracle@rac3:/opt/oracle/11.2.0/alifpre/network/admin>tnsping rac2
TNS Ping Utility for Linux: Version 11.2.0.1.0 - Production on 15-DEC-2011 16:19:48
Copyright (c) 1997, 2009, Oracle. All rights reserved.
Used parameter files:
/opt/oracle/11.2.0/alifpre/network/admin/sqlnet.ora
Used TNSNAMES adapter to resolve the alias
Attempting to contact (DESCRIPTION = (ADDRESS_LIST = (ADDRESS = (PROTOCOL = TCP)(HOST = 10.250.7.112)(PORT = 1521))) (CONNECT_DATA = (SID = rac2)))
TNS-12547: TNS:lost contact
分别修改rac1 rac2 的 sqlnet.ora文件
grid@rac2:/opt/11202/11.2.0/grid/network/admin>vim sqlnet.ora
NAMES.DIRECTORY_PATH= (TNSNAMES, EZCONNECT)
tcp.validnode_checking=yes
#允许访问的ip
tcp.invited_nodes =(10.250.7.249,10.250.7.241)
ADR_BASE = /opt/rac/grid
3 修改之后必须重启监听，(这个对于生产库比较麻烦,最造成操作期间的新连接失败)
grid@rac2:/opt/11202/11.2.0/grid/network/admin>srvctl stop listener
grid@rac2:/opt/11202/11.2.0/grid/network/admin>srvctl start listener
grid@rac1:/opt/11202/11.2.0/grid/network/admin>vim sqlnet.ora
NAMES.DIRECTORY_PATH= (TNSNAMES, EZCONNECT)
tcp.validnode_checking=yes
#允许访问的ip
tcp.invited_nodes =(10.250.7.225,10.250.7.241)
ADR_BASE = /opt/rac/grid
重启监听！
grid@rac1:/opt/11202/11.2.0/grid/network/admin>srvctl stop listener
grid@rac1:/opt/11202/11.2.0/grid/network/admin>srvctl start listener
4 再次进行测试：
oracle@rac3:/opt/oracle/11.2.0/alifpre/network/admin>tnsping rac2
Attempting to contact (DESCRIPTION = (ADDRESS_LIST = (ADDRESS = (PROTOCOL = TCP)(HOST = 10.250.7.112)(PORT = 1521))) (CONNECT_DATA = (SID = rac2)))
OK (0 msec)
oracle@rac3:/opt/oracle/11.2.0/alifpre/network/admin>tnsping rac1
Attempting to contact (DESCRIPTION = (ADDRESS_LIST = (ADDRESS = (PROTOCOL = TCP)(HOST = 10.250.7.225)(PORT = 1521))) (CONNECT_DATA = (SID = rac1)))
OK (10 msec)
成功配置！