At one time, OS X
didn't consult the hosts file before doing a DNS lookup. In 10.3 and 10.4, it does. You can check the name resolution order of your Mac using Terminal; enter the following:
lookupd -configuration
Look for the following in the output:
LookupOrder: Cache FF DNS NI DS
_config_name: Host Configuration
The
FF (flat file) refers to your hosts file (
/etc/hosts), and Tiger does check its contents before going to DNS and Netinfo. Just a little FYI for those who may not have realized that 10.4 fixed things.