rac vip failback issue

測試從交換機上或者資料庫主機端關閉eth0（public nic 240/242）

拔網線的效果也一樣,任一一個網路卡，vip漂移正常。

重啟原來網路卡後，vip漂移回來，但交換機收到arp包，將vip的mac地址設定為全0，

從而導致網外無法正常連線到failback 回來的vip地址。

Mac 緩衝更新後，恢復正常。

目前交換機設定的mac地址失效時間為4小時。

在某些情況下，例如這個case，mac地址重新整理造成vip failback後在一段時間內不可用。

10.2.0.4 and 11.1版本中，vip預設不做failback，在11gr2中，預設是failback的。

解決方法：

（1）取消自動failback，修改 $ORACLE_HOME/bin/racgwrap 指令碼，啟用：

ORA_RACG_VIP_FAILBACK=1 && export ORA_RACG_VIP_FAILBACK

（2）縮短交換機mac地址快取時間，由於可能影響整個vlan，所以昨天沒有測試。

（3）手工重定位或者呼叫指令碼，vip漂移後，重新廣播新的地址。  arping  -c 5 -U -I eth0 $vipaddress

文件和相關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Bug 11069846  Gratuitous ARP packets must be targeted to router to avoid connectivity problems - superceded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 Note that this fix has been superceded by the fix in Bug:13440962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HOOKS CAUSES:13440962 SUPERCEDED:13440962 LIKELYAFFECTS XAFFECTS_11.2.0.1 XAFFECTS_V11020001 AFFECTS=11.2.0.1 XAFFECTS_11.2.0.2 XAFFECTS_V11020002 AFFECTS=11.2.0.2 XPRODID_5 PRODUCT_ID=5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