测试从交换机上或者数据库主机端关闭eth0（public nic 240/242）

拔网线的效果也一样,任一一个网卡，vip漂移正常。

重启原来网卡后，vip漂移回来，但交换机收到arp包，将vip的mac地址设置为全0，

从而导致网外无法正常连接到failback 回来的vip地址。

Mac 缓冲更新后，恢复正常。

目前交换机设置的mac地址失效时间为4小时。

在某些情况下，例如这个case，mac地址刷新造成vip failback后在一段时间内不可用。

10.2.0.4 and 11.1版本中，vip默认不做failback，在11gr2中，默认是failback的。

解决方法：

（1）取消自动failback，修改 $ORACLE_HOME/bin/racgwrap 脚本，启用：

ORA_RACG_VIP_FAILBACK=1 && export ORA_RACG_VIP_FAILBACK

（2）缩短交换机mac地址缓存时间，由于可能影响整个vlan，所以昨天没有测试。

（3）手工重定位或者调用脚本，vip漂移后，重新广播新的地址。  arping  -c 5 -U -I eth0 $vipaddress

文档和相关bug：

VIP does not relocate back to the original node starting from 10.2.0.4 and 11.1 even after the public network problem is resolved. [ID 805969.1]

Bug 11069846  Gratuitous ARP packets must be targeted to router to avoid connectivity problems - superceded

 This note gives a brief overview of bug 11069846.
 The content was last updated on: 01-FEB-2012
 Click here for details of each of the sections below.

Affects:

 Note that this fix can cause / expose the problem described in Bug:13440962

 Note that this fix has been superceded by the fix in Bug:13440962

Fixed:

Description

Note: 

 This fix can cause the problem described in bug 13440962. 

 Please use that fix instead of this one.

After failover, the SCAN/VIP addresses are sometimes not reachable from 

outside the network after normal startup.  When this connectivity problem

exists, the addresses are reachable from within the network (subnet), 

but not from outside.  

Rediscovery Notes:

 Router ARP cache is not refreshing (router still thinks the IP belongs 

 to the old MAC address) when the SCAN/VIP addresses move from one node 

 to the other

Workaround

 None

HOOKS CAUSES:13440962 SUPERCEDED:13440962 LIKELYAFFECTS XAFFECTS_11.2.0.1 XAFFECTS_V11020001 AFFECTS=11.2.0.1 XAFFECTS_11.2.0.2 XAFFECTS_V11020002 AFFECTS=11.2.0.2 XPRODID_5 PRODUCT_ID=5 PRODID-5 PCW XCOMP_PCW COMPONENT=PCW TAG_OPSM OPSM FIXED_11.2.0.3 FIXED_12.1.0.0

References

Bug:11069846 (This link will only work for PUBLISHED bugs)
Note:245840.1 Information on the sections in this article

Bug 13440962  Different subnet failed to connect to vip after restart vip

 This note gives a brief overview of bug 13440962. 
 The content was last updated on: 01-FEB-2012
 Click here for details of each of the sections below.

Affects:

 It is believed to be a regression in default behaviour thus:
   Regression introduced in 11.2.0.3

Fixed:

Description

This is a regression fix for problem introduced by patch 11069846. 

The change in this patch (patch 13440962) fixes a problem with 4 extra 

bytes in the GARP message and removes an extra unicast GARP packet to 

the router.

Rediscovery Notes:

 After upgrading to 11.2.0.3, after vip failover, the ip address is 

 not pingable from a different subnet on Linux. 

 (This problem is seen only on Linux)

Workaround

 After vip failover, run command 

   /sbin/arping -U -c 3 -I   

 to update the ARP table of router. 

References

Bug:13440962 (This link will only work for PUBLISHED bugs)
Note:245840.1 Information on the sections in this article