As yesterday i was installation CRS and i got stuck on Network Configuration Screen, where i have to fill the Public, Virtual & Private network IPs... i was getting following error i.e.
You must enter unique values for the public node name, the private node name and the virtual hostname for all nodes in the cluster. The name, YOUR-HOSTNAME , that you entered is being used by more than once for the same node.
The virtual hostname(s), YOUR-HOSTNAME, you have specified appears to be already assigned to another system on the network. Please ensure that the virtual hostname(s) that you use for each of the nodes in the cluster are not in use currently.
after reading the ORACLE official documentation and testing the provided machine's configuration i found that, my installation server had name resolution problem, firstly our DNS was resolving hostname on wrong IP and later when they changed it to resolve from /etc/hosts it was unable to resolve from this file...anyhow later with investigation i was able to give a brief idea that how CRS IP Network Configuration should look like, its simple ! here it is:
You should have three IPs/Hostname i.e.
1. Public Hostname/IP (Physical Interface):
Public Hostname should register in DNS or /etc/hosts file and should be accessible i.e. one can ping it.
2. VIP Hostname/IP(Logical Interface):
VIP Hostname/IP should register in DNS or /etc/hosts file and should NOT be accessible i.e. one CANNOT ping it.
NOTE: in case of IPMP VIP should be LOGICAL interface.
3. Private Hostname/IP(Physical Interface):
Private Hostname should register in DNS or /etc/hosts file and should be accessible i.e. one can ping it.