更改10g RAC公网IP以及VIP的简单步骤：
1. Stop all crs resources
标准操作步骤，参考另一帖子：
http://space.itpub.net/628922/viewspace-690171 
2. Modify /etc/hosts 
这里修改以后为如下：

[oracle@hsdb1 admin]$ cat /etc/hosts
# Do not remove the following line, or various programs
# that require network functionality will fail.
 
127.0.0.1        localhost.localdomain localhost
::1              localhost6.localdomain6 localhost6
 
#### for oracle rac
 
192.168.5.220    hsdb1
192.168.5.222    hsdb1-vip
10.10.10.1       hsdb1-priv
 
192.168.5.221    hsdb2
192.168.5.223    hsdb2-vip
10.10.10.2       hsdb2-priv
(注：RAC中所有节点都需要进行修改。)

3. Change $ORACLE_HOME/network/admin/listener.ora
这里修改以后如下:
[oracle@hsdb1 admin]$ cat listener.ora
……………………………………………………………………………………………………
LISTENER_HSDB1 =
  (DESCRIPTION_LIST =
    (DESCRIPTION =
      (ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC))
      (ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.5.222)(PORT = 1521)(IP = FIRST))
      (ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.5.220)(PORT = 1521)(IP = FIRST))
    )
  )

(注：如果这里host你用的name，那么不必进行修改。)

4. Delete Public eth0 (在其中一个node操作即可)
[root@localhost bin]# ./oifcfg getif

eth0  192.168.1.0  global  public
eth1  10.10.10.0   global  cluster_interconnect
 
[root@localhost bin]# ./oifcfg delif -global eth0

[root@localhost bin]# ./oifcfg getif

eth1  10.10.10.0   global  cluster_interconnect

5. Add new public eth0
[root@localhost bin]# ./oifcfg setif -global eth0/192.168.5.0:public
 
[root@localhost bin]# ./oifcfg getif


eth0  192.168.5.0  global  public    <== 新的网段
eth1  10.10.10.0   global  cluster_interconnect
 
(注：因为vip地址必须跟public ip处于同一网段，故公网IP网段更改以后，必须更改vip地址或网段。)

6. Change vip
++++++ Node 1 ++++++
[root@hsdb1 bin]# ./srvctl modify nodeapps -n hsdb1 -A 192.168.5.222/255.255.255.0/eth0
 
++++++ Node 2 ++++++
[root@hsdb2 bin]# ./srvctl modify nodeapps -n hsdb2 -A 192.168.5.223/255.255.255.0/eth0

7. Start cluster all resource
参考另一个帖子：
http://space.itpub.net/628922/viewspace-690171
crs_stat -t 如果有OFFLINE的resource，手工crs_start启动即可

8. Change local_listener
++++++ Node 1 ++++++

SQL>show parameter listener

NAME				     TYPE	 VALUE
------------------------------------ ----------- ------------------------------
local_listener			     string	 (ADDRESS=(PROTOCOL=tcp)(HOST=1
						 92.168.1.222)(PORT=1521))

SQL>ALTER system SET local_listener = '(ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.5.222)(PORT = 1521))' scope = BOTH sid = 'hskj1';
 
System altered.

++++++ Node 2 ++++++

SQL> ALTER system SET local_listener = '(ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.5.223)(PORT = 1521))' scope = BOTH sid = 'hskj2';

System altered.

另外，ssh等效性不需要重新配置。

转载一个step by step change public-ip and vip on RAC