The first is an IP address, the second is the full name (including domain)
of the machine, and the third is a nickname (usually just the hostname).
Do this for all IP's...
192.168.0.1 ip-0-1.internal.net ip-0-1
192.168.0.2 ip-0-2.internal.net ip-0-2
ad infinitum. If you are using this address space as a Class B, I
*strongly* suggest you do this in Excel, where you can autonumber and
create the 65,536 lines you need in about 30 seconds, then export to
notepad, then upload to server, cut/paste into /etc/hosts. Otherwise,
well... you're going to be here for a while.