Bonding, IP alias, Virtual IP, 2 nodes cluster

Hi ! I have a simple setup of 2 PC (with linux Red-Hat) where the first PC is the primary machine and the second the backup. I use DRBD for data replication and Red-Hat cluster suite for HA (High Availability). I have tested both.

Now I NEED a COMMON IP ADDRESS (or Master/unique IP address) for my two system. When the primary machine fails (or shutdown), the backup system will do the job. From the external world, client who connect to my cluster will "connect to one address" or virtual IP and won't know if this is the primary system or the backup.

For now, my 2 machines have the same /etc/hosts file:

which contains: 10.60.1.23 PrimaryMachine
10.60.1.77 BackupMachine

Maybe I need to change the IP address for something local (192.168.1.0), I don't know. Theses address where created dynamically I think with DHCP when I installed Red-Hat on both machine.

I red many document about BONDING, IP ALIAS and VIRTUAL IP but now I am LOST !!!

What I do really need (keep it as simple as possible) and how to do it ???

Thank you very much.