How to deallocate alias IP from AIX HACMP cluster.

How to deallocate alias service IP on AIX hacmp cluster.

Scenario:

we had request for deallocation of service IP from AIX hacmp node and assign that same IP  on Linux platform server.
So here application team moving there app from AIX to Linux so they want same IP address which is currently assigned on AIX hacmp node.

Solution :

How we can deallocate service IP from AIX hacmp node, answer to this query is simply bring down resource group to which service IP belong.

Steps followed for doing this activity:


IP address befor bringing down resource group


root@:/root : ifconfig -a
en0: BROADCAST,NOTRAILERS,RUNNING,SIMPLEX,MULTICAST,GROUPRT,64BIT,CHECKSUM_OFFLOAD(ACTIVE),LARGESEND,CHAIN>
        inet 192.168.1.XX netmask broadcast
        inet 10.1.XXX.XXX netmask broadcast
         tcp_sendspace 262144 tcp_recvspace 262144 rfc1323 1


Here service IP is 10.1.XXX.XXX , so we need to bring down 10.1.XXX.XXX.


Step 1:

root@/root : clRGinfo
--------------------------------------------------------------------------------------
Group Name                   Group State      Node
---------------------------------------------------------------------------------------
rg_app1                   ONLINE           node1     // IP is in rg_app1 Resource group
                          OFFLINE          node2


Step 2:

Stop resource group using smitty clstop


                                                             Stop Cluster Services

Type or select values in entry fields.
Press Enter AFTER making all desired changes.

                                                        [Entry Fields]
* Stop now, on system restart or both                 now                                                                                      +
  Stop Cluster Services on these nodes               [node1]                                                                         +
  BROADCAST cluster shutdown?                         false                                                                                    +
* Select an Action on Resource Groups                 Bring Resource Groups Offline


Step 3:

once stopped confirm uing following command

root@/root : clRGinfo
--------------------------------------------------------------------------------------
Group Name                   Group State      Node
---------------------------------------------------------------------------------------
rg_app1                   OFFLINE           node1     // here rg_app1 is OFFLINE.
                          OFFLINE          node2



Step 4:

After resource group offline alias IP also got deallocated from interface en0.
if you observed ifconfig -a ouput you will see that alias service IP down after Resource group stop.

root@:/root : ifconfig -a
en0: BROADCAST,NOTRAILERS,RUNNING,SIMPLEX,MULTICAST,GROUPRT,64BIT,CHECKSUM_OFFLOAD(ACTIVE),LARGESEND,CHAIN>
        inet 192.168.1.XX netmask  broadcast


What about non-hacmp AIX server , in that situation you need to bring down AIX host or other option is bring down that interface from HMC console.
why HMC console ??

Because after interface down AIX admin also able to access AIX LPAR, but if admin using putty ssh seesion then after interface down then server
will be not reachable from putty ssh. It will only accessible from HMC console.

     
     



Thanks !!!!