How to install Oracle 11g R2 RAC without SCAN Setup in DNS or GNS?

If you would like to Install Oracle 11g R2 RAC without SCAN setup in DNS, you would need to create an entry in /etc/hosts for the scan name to point to a different IP address (other than Public IP, Private IP, and VIP addresses) and supply this name for SCAN Prompts during the installation. Make sure that you pick the new IP address in the same subnet as that of VIP addresses and that it is not currently in use.

[root@rac1 ~]# cat /etc/hosts

# Do not remove the following line, or various programs

# that require network functionality will fail.

127.0.0.1               localhost.localdomain localhost

# Public

192.168.1.10   rac1.freeoraclehelp.com     rac1

192.168.1.20   rac2.freeoraclehelp.com     rac2

#Private

192.168.2.10   rac1-priv.freeoraclehelp.com  rac1-priv

192.168.2.20   rac2-priv.freeoraclehelp.com  rac2-priv

#Virtual

192.168.1.11   rac1-vip.freeoraclehelp.com   rac1-vip

192.168.1.22   rac2-vip.freeoraclehelp.com   rac2-vip

#SCAN Entry

192.168.1.25   scan.freeoraclehelp.com   scan

[root@rac1 ~]# 

**** SCAN & VIP has same subnet

Ref: http://www.freeoraclehelp.com/2011/12/scan-setup-for-oracle-11g-release211gr2.html#WHATISSCANINORAC