10.2.0.4以后vip不会自动relocate back回原节点， 原因是ORACLE开发人员发现在实际使用中会遇到这样的情况： relocate back回原节点 需要停止VIP并在原始节点再次启动该VIP，但是如果原始节点上的公共网络仍不可用，则这个relocate的尝试将再次失败而failover到第二节点。 在此期间VIP将不可用，所以从10.2.0.4和11.1开始，默认的实例检查将不会自动relocate vip到原始节点。
详细见下面的Note介绍：
Applies to:
Oracle Server – Enterprise Edition – Version 10.2.0.4 to 11.1.0.7 [Release 10.2 to 11.1]
Information in this document applies to any platform.
Symptoms
Starting from 10.2.0.4 and 11.1, VIP does not fail-over back to the original node even after the public network problem is resolved. This behavior is the default behavior in 10.2.0.4 and 11.1 and is different from that of 10.2.0.3
Cause
This is actually the default default behavior in 10.2.0.4 and 11.1
In 10.2.0.3, on every instance check, the instance attempted to relocate the VIP back to the preferred node (original node), but that required stopping the VIP and then attempt to restart the VIP on the original node. If the public network on the original node is still down, then the attempt to relocate VIP to the original node will fail and the VIP will fail-over back to the secondary node. During this time, the VIP is not available, so starting from 10.2.0.4 and 11.1, the default behavior is that the instance check will not attempt to relocate the VIP back to the original node.
Solution
If the default behavior of 10.2.0.4 and 11.1 is not desired and if there is a need to have the VIP relocate back to the original node automatically when the public network problem is resolved, use the following workaround
Uncomment the line
ORA_RACG_VIP_FAILBACK=1 && export ORA_RACG_VIP_FAILBACK
in the racgwrap script in $ORACLE_HOME/bin
With the above workaround, VIP will relocate back to the original node when CRS performs the instance check, so in order for the VIP to relocate automatically, the node must have at least one instance running.
The instance needs to be restarted or CRS needs to be restarted to have the VIP start relocating back to the original node automatically if the change is being made on the existing cluster.
Relying on automatic relocation of VIP can take up to 10 minutes because the instance check is performed once every 10 minutes. Manually relocating the VIP is only way to guarantee quick relocation of VIP back to the original node.
To manually relocate the VIP, start the nodeapps by issuing
srvctl start nodeapps -n <node name>
Starting the nodeapps does not harm the online resources such as ons and gsd.
