How to Change Interconnect/Public Interface IP Subnet in a 10g Cluster

This  document explains  how to change or update the cluster_interconnect and/or public interface IP information that is stored in the OCR

If  subnet or interface is  not  changed  only IP  is changed  then you can follow 

Modifying the VIP ,VIP Hostname of RAC Clusterware Node

else  if subnet is changed  then  you can change the interface information for a cluster using the following as an example

1. Use the getif option to show the currently configured interfaces
   $CRS_HOME/bin/oifcfg getif
   eth0 10.2.156.0 global public
   eth1 192.168.0.0 global cluster_interconnect
2. If the public interface IP needs to be changed, there is not a 'modify' option - you will need to delete the interface and add it back with the correct subnet
   $CRS_HOME/bin/oifcfg delif -global eth0
   $CRS_HOME/bin/oifcfg setif –global eth0/10.2.166.0:public
3. The same step could be use for the private interface:
   $CRS_HOME/bin/oifcfg delif –global eth1
   $CRS_HOME/bin/oifcfg setif –global eth1/192.168.1.0:cluster_interconnect
4. Verify the correct interface subnet is in use by re-running oifcfg with the 'getif' option
   $CRS_HOME/bin/oifcfg getif
   eth0 10.2.166.0 global public
   eth1 192.168.1.0 global cluster_interconnect