Identify which interface that you should modify.
[grid@oda0 ~]$ oifcfg getif -global
bond0 10.0.18.0 global public
ibbond0 192.168.2.0 global cluster_interconnect,asm
OK, we found bond0 is the public IP interface.
Modify /etc/sysconfig/network-scripts/ifcfg-bond0.
[root@oda0 ~]$ vi /etc/sysconfig/network-scripts/ifcfg-bond0
...
IPADDR=10.0.18.5
#IPADDR=10.0.18.218
...
Modify /etc/hosts and DNS
[root@oda0 ~]$ vi /etc/hosts
...
10.0.18.5 oda0 oda0.example.com
#10.0.18.218 oda0 oda0.example.com
Restart network
[root@oda0 ~]$ service network restart
You may lost connection to the console.
Restart clusterware stack by root.
[root@oda0 ~]# export PATH=$PATH:/u01/app/12.1.0.2/grid/bin
[root@oda0 ~]# which crsctl
/u01/app/12.1.0.2/grid/bin/crsctl
Stop cluster stack.
[root@oda0 ~]# crsctl stop cluster -all
CRS-2673: Attempting to stop 'ora.crsd' on 'oda0'
CRS-2790: Starting shutdown of Cluster Ready Services-managed resources on 'oda0'
CRS-2673: Attempting to stop 'ora.flash.flashdata.acfs' on 'oda0'
CRS-2673: Attempting to stop 'ora.RECO.dg' on 'oda0'
CRS-2673: Attempting to stop 'ora.reco.acfsvol.acfs' on 'oda0'
CRS-2673: Attempting to stop 'ora.LISTENER_SCAN1.lsnr' on 'oda0'
CRS-2673: Attempting to stop 'ora.data.datastore.acfs' on 'oda0'
CRS-2673: Attempting to stop 'ora.redo.datastore.acfs' on 'oda0'
CRS-2673: Attempting to stop 'ora.reco.datastore.acfs' on 'oda0'
CRS-2673: Attempting to stop 'ora.LISTENER.lsnr' on 'oda0'
CRS-2677: Stop of 'ora.RECO.dg' on 'oda0' succeeded
CRS-2673: Attempting to stop 'ora.REDO.dg' on 'oda0'
CRS-2673: Attempting to stop 'ora.DATA.dg' on 'oda0'
CRS-2673: Attempting to stop 'ora.FLASH.dg' on 'oda0'
CRS-2677: Stop of 'ora.FLASH.dg' on 'oda0' succeeded
CRS-2677: Stop of 'ora.REDO.dg' on 'oda0' succeeded
CRS-2677: Stop of 'ora.DATA.dg' on 'oda0' succeeded
CRS-2673: Attempting to stop 'ora.asm' on 'oda0'
CRS-2677: Stop of 'ora.LISTENER_SCAN1.lsnr' on 'oda0' succeeded
CRS-2673: Attempting to stop 'ora.scan1.vip' on 'oda0'
CRS-2677: Stop of 'ora.LISTENER.lsnr' on 'oda0' succeeded
CRS-2673: Attempting to stop 'ora.oda0.vip' on 'oda0'
CRS-2677: Stop of 'ora.asm' on 'oda0' succeeded
CRS-2673: Attempting to stop 'ora.ASMNET1LSNR_ASM.lsnr' on 'oda0'
CRS-2673: Attempting to stop 'ora.crsd' on 'oda1'
CRS-2790: Starting shutdown of Cluster Ready Services-managed resources on 'oda1'
CRS-2673: Attempting to stop 'ora.LISTENER.lsnr' on 'oda1'
CRS-2673: Attempting to stop 'ora.oc4j' on 'oda1'
CRS-2673: Attempting to stop 'ora.LISTENER_SCAN2.lsnr' on 'oda1'
CRS-2673: Attempting to stop 'ora.cvu' on 'oda1'
CRS-2677: Stop of 'ora.cvu' on 'oda1' succeeded
CRS-2677: Stop of 'ora.ASMNET1LSNR_ASM.lsnr' on 'oda0' succeeded
CRS-2677: Stop of 'ora.LISTENER.lsnr' on 'oda1' succeeded
CRS-2673: Attempting to stop 'ora.oda1.vip' on 'oda1'
CRS-2677: Stop of 'ora.LISTENER_SCAN2.lsnr' on 'oda1' succeeded
CRS-2673: Attempting to stop 'ora.scan2.vip' on 'oda1'
CRS-2677: Stop of 'ora.scan1.vip' on 'oda0' succeeded
CRS-2677: Stop of 'ora.flash.flashdata.acfs' on 'oda0' succeeded
CRS-2677: Stop of 'ora.oda0.vip' on 'oda0' succeeded
CRS-2677: Stop of 'ora.reco.acfsvol.acfs' on 'oda0' succeeded
CRS-2673: Attempting to stop 'ora.RECO.ACFSVOL.advm' on 'oda0'
CRS-2677: Stop of 'ora.RECO.ACFSVOL.advm' on 'oda0' succeeded
CRS-2677: Stop of 'ora.oda1.vip' on 'oda1' succeeded
CRS-2677: Stop of 'ora.scan2.vip' on 'oda1' succeeded
CRS-2677: Stop of 'ora.redo.datastore.acfs' on 'oda0' succeeded
CRS-2677: Stop of 'ora.oc4j' on 'oda1' succeeded
CRS-2677: Stop of 'ora.data.datastore.acfs' on 'oda0' succeeded
CRS-2673: Attempting to stop 'ora.DATA.DATASTORE.advm' on 'oda0'
CRS-2673: Attempting to stop 'ora.FLASH.ACLDATSTORE.advm' on 'oda0'
CRS-2677: Stop of 'ora.DATA.DATASTORE.advm' on 'oda0' succeeded
CRS-2677: Stop of 'ora.FLASH.ACLDATSTORE.advm' on 'oda0' succeeded
CRS-2677: Stop of 'ora.reco.datastore.acfs' on 'oda0' succeeded
CRS-2673: Attempting to stop 'ora.RECO.DATASTORE.advm' on 'oda0'
CRS-2677: Stop of 'ora.RECO.DATASTORE.advm' on 'oda0' succeeded
CRS-2673: Attempting to stop 'ora.FLASH.FLASHDATA.advm' on 'oda0'
CRS-2673: Attempting to stop 'ora.REDO.DATASTORE.advm' on 'oda0'
CRS-2677: Stop of 'ora.FLASH.FLASHDATA.advm' on 'oda0' succeeded
CRS-2677: Stop of 'ora.REDO.DATASTORE.advm' on 'oda0' succeeded
CRS-2673: Attempting to stop 'ora.redo.datastore.acfs' on 'oda1'
CRS-2673: Attempting to stop 'ora.proxy_advm' on 'oda0'
CRS-2677: Stop of 'ora.redo.datastore.acfs' on 'oda1' succeeded
CRS-2673: Attempting to stop 'ora.REDO.DATASTORE.advm' on 'oda1'
CRS-2677: Stop of 'ora.REDO.DATASTORE.advm' on 'oda1' succeeded
CRS-2673: Attempting to stop 'ora.REDO.dg' on 'oda1'
CRS-2673: Attempting to stop 'ora.data.datastore.acfs' on 'oda1'
CRS-2673: Attempting to stop 'ora.flash.flashdata.acfs' on 'oda1'
CRS-2673: Attempting to stop 'ora.reco.acfsvol.acfs' on 'oda1'
CRS-2673: Attempting to stop 'ora.reco.datastore.acfs' on 'oda1'
CRS-2677: Stop of 'ora.REDO.dg' on 'oda1' succeeded
Error unmounting '/cloudfs'. Possible busy file system. Verify the logs.
CRS-2677: Stop of 'ora.reco.acfsvol.acfs' on 'oda1' succeeded
CRS-2673: Attempting to stop 'ora.RECO.ACFSVOL.advm' on 'oda1'
CRS-2677: Stop of 'ora.RECO.ACFSVOL.advm' on 'oda1' succeeded
Error unmounting '/u02/app/oracle/oradata/datastore'. Possible busy file system. Verify the logs.
CRS-2677: Stop of 'ora.data.datastore.acfs' on 'oda1' succeeded
CRS-2673: Attempting to stop 'ora.DATA.DATASTORE.advm' on 'oda1'
CRS-2673: Attempting to stop 'ora.FLASH.ACLDATSTORE.advm' on 'oda1'
CRS-2677: Stop of 'ora.FLASH.ACLDATSTORE.advm' on 'oda1' succeeded
CRS-2677: Stop of 'ora.DATA.DATASTORE.advm' on 'oda1' succeeded
CRS-2673: Attempting to stop 'ora.mgmtdb' on 'oda1'
CRS-2677: Stop of 'ora.proxy_advm' on 'oda0' succeeded
CRS-2673: Attempting to stop 'ora.net1.network' on 'oda0'
CRS-2677: Stop of 'ora.net1.network' on 'oda0' succeeded
CRS-2792: Shutdown of Cluster Ready Services-managed resources on 'oda0' has completed
Error unmounting '/u02/app/oracle/oradata/flashdata'. Possible busy file system. Verify the logs.
CRS-2677: Stop of 'ora.flash.flashdata.acfs' on 'oda1' succeeded
CRS-2673: Attempting to stop 'ora.FLASH.FLASHDATA.advm' on 'oda1'
CRS-2677: Stop of 'ora.FLASH.FLASHDATA.advm' on 'oda1' succeeded
CRS-2677: Stop of 'ora.crsd' on 'oda0' succeeded
CRS-2673: Attempting to stop 'ora.ctssd' on 'oda0'
CRS-2673: Attempting to stop 'ora.evmd' on 'oda0'
CRS-2673: Attempting to stop 'ora.storage' on 'oda0'
CRS-2677: Stop of 'ora.storage' on 'oda0' succeeded
CRS-2673: Attempting to stop 'ora.asm' on 'oda0'
Error unmounting '/u01/app/oracle/fast_recovery_area/datastore'. Possible busy file system. Verify the logs.
CRS-2677: Stop of 'ora.reco.datastore.acfs' on 'oda1' succeeded
CRS-2673: Attempting to stop 'ora.RECO.DATASTORE.advm' on 'oda1'
CRS-2677: Stop of 'ora.RECO.DATASTORE.advm' on 'oda1' succeeded
CRS-2673: Attempting to stop 'ora.proxy_advm' on 'oda1'
CRS-2677: Stop of 'ora.ctssd' on 'oda0' succeeded
CRS-2677: Stop of 'ora.evmd' on 'oda0' succeeded
CRS-2677: Stop of 'ora.mgmtdb' on 'oda1' succeeded
CRS-2673: Attempting to stop 'ora.DATA.dg' on 'oda1'
CRS-2673: Attempting to stop 'ora.MGMTLSNR' on 'oda1'
CRS-2677: Stop of 'ora.DATA.dg' on 'oda1' succeeded
CRS-2677: Stop of 'ora.MGMTLSNR' on 'oda1' succeeded
CRS-2677: Stop of 'ora.proxy_advm' on 'oda1' succeeded
CRS-2673: Attempting to stop 'ora.FLASH.dg' on 'oda1'
CRS-2673: Attempting to stop 'ora.RECO.dg' on 'oda1'
CRS-2677: Stop of 'ora.FLASH.dg' on 'oda1' succeeded
CRS-2677: Stop of 'ora.RECO.dg' on 'oda1' succeeded
CRS-2673: Attempting to stop 'ora.asm' on 'oda1'
CRS-2677: Stop of 'ora.asm' on 'oda0' succeeded
CRS-2673: Attempting to stop 'ora.cluster_interconnect.haip' on 'oda0'
CRS-2677: Stop of 'ora.cluster_interconnect.haip' on 'oda0' succeeded
CRS-2673: Attempting to stop 'ora.cssd' on 'oda0'
CRS-2677: Stop of 'ora.asm' on 'oda1' succeeded
CRS-2673: Attempting to stop 'ora.ASMNET1LSNR_ASM.lsnr' on 'oda1'
CRS-2677: Stop of 'ora.ASMNET1LSNR_ASM.lsnr' on 'oda1' succeeded
CRS-2673: Attempting to stop 'ora.ons' on 'oda1'
CRS-2677: Stop of 'ora.ons' on 'oda1' succeeded
CRS-2673: Attempting to stop 'ora.net1.network' on 'oda1'
CRS-2677: Stop of 'ora.net1.network' on 'oda1' succeeded
CRS-2792: Shutdown of Cluster Ready Services-managed resources on 'oda1' has completed
CRS-2677: Stop of 'ora.cssd' on 'oda0' succeeded
CRS-2677: Stop of 'ora.crsd' on 'oda1' succeeded
CRS-2673: Attempting to stop 'ora.ctssd' on 'oda1'
CRS-2673: Attempting to stop 'ora.evmd' on 'oda1'
CRS-2673: Attempting to stop 'ora.storage' on 'oda1'
CRS-2677: Stop of 'ora.storage' on 'oda1' succeeded
CRS-2673: Attempting to stop 'ora.asm' on 'oda1'
CRS-2677: Stop of 'ora.ctssd' on 'oda1' succeeded
CRS-2677: Stop of 'ora.evmd' on 'oda1' succeeded
CRS-2677: Stop of 'ora.asm' on 'oda1' succeeded
CRS-2673: Attempting to stop 'ora.cluster_interconnect.haip' on 'oda1'
CRS-2677: Stop of 'ora.cluster_interconnect.haip' on 'oda1' succeeded
CRS-2673: Attempting to stop 'ora.cssd' on 'oda1'
CRS-2677: Stop of 'ora.cssd' on 'oda1' succeeded
Start cluster stack.
[root@oda0 ~]# crsctl start cluster -all
CRS-2672: Attempting to start 'ora.cssdmonitor' on 'oda0'
CRS-2672: Attempting to start 'ora.cssdmonitor' on 'oda1'
CRS-2672: Attempting to start 'ora.evmd' on 'oda0'
CRS-2672: Attempting to start 'ora.evmd' on 'oda1'
CRS-2676: Start of 'ora.cssdmonitor' on 'oda1' succeeded
CRS-2676: Start of 'ora.cssdmonitor' on 'oda0' succeeded
CRS-2672: Attempting to start 'ora.cssd' on 'oda0'
CRS-2672: Attempting to start 'ora.cssd' on 'oda1'
CRS-2672: Attempting to start 'ora.diskmon' on 'oda1'
CRS-2672: Attempting to start 'ora.diskmon' on 'oda0'
CRS-2676: Start of 'ora.diskmon' on 'oda1' succeeded
CRS-2676: Start of 'ora.diskmon' on 'oda0' succeeded
CRS-2676: Start of 'ora.evmd' on 'oda1' succeeded
CRS-2676: Start of 'ora.evmd' on 'oda0' succeeded
CRS-2676: Start of 'ora.cssd' on 'oda1' succeeded
CRS-2672: Attempting to start 'ora.ctssd' on 'oda1'
CRS-2672: Attempting to start 'ora.cluster_interconnect.haip' on 'oda1'
CRS-2676: Start of 'ora.cssd' on 'oda0' succeeded
CRS-2672: Attempting to start 'ora.ctssd' on 'oda0'
CRS-2672: Attempting to start 'ora.cluster_interconnect.haip' on 'oda0'
CRS-2676: Start of 'ora.ctssd' on 'oda1' succeeded
CRS-2676: Start of 'ora.ctssd' on 'oda0' succeeded
CRS-2676: Start of 'ora.cluster_interconnect.haip' on 'oda1' succeeded
CRS-2672: Attempting to start 'ora.asm' on 'oda1'
CRS-2676: Start of 'ora.cluster_interconnect.haip' on 'oda0' succeeded
CRS-2672: Attempting to start 'ora.asm' on 'oda0'
CRS-2676: Start of 'ora.asm' on 'oda0' succeeded
CRS-2672: Attempting to start 'ora.storage' on 'oda0'
CRS-2676: Start of 'ora.asm' on 'oda1' succeeded
CRS-2672: Attempting to start 'ora.storage' on 'oda1'
CRS-2676: Start of 'ora.storage' on 'oda1' succeeded
CRS-2672: Attempting to start 'ora.crsd' on 'oda1'
CRS-2676: Start of 'ora.crsd' on 'oda1' succeeded
CRS-2676: Start of 'ora.storage' on 'oda0' succeeded
CRS-2672: Attempting to start 'ora.crsd' on 'oda0'
CRS-2676: Start of 'ora.crsd' on 'oda0' succeeded
Normally, the clusterware will mount all related partitions back within 2 minutes after cluster restarted, but if the mount points did not come back eventually, you can manually do the job.
[root@oda0 ~]# mount -a
Startup the database
[oracle@oda0 ~]$ sqlplus / as sysdba
...
SQL> startup
ORACLE instance started.
Total System Global Area 6.8413E+10 bytes
Fixed Size 2270360 bytes
Variable Size 5637147496 bytes
Database Buffers 6.2680E+10 bytes
Redo Buffers 93585408 bytes
Database mounted.
Database opened.
For changing a whole subnet for a RAC database, it's little tougher than this.