I have a Windows 7 computer and a MacOS X 10.6 computer that are connected to the same LAN using a 10$ hub. On MacOS I set the computer name to "mymac.local" in "preferences->sharing". The Windows computer has a static IP address of 192.168.0.10 and the Mac has the address 192.168.0.20. Both have a netmask of 255.255.255.0 and no gateway.
If I issue the command
ping mymac.local from my Windows computer it will successfully ping 192.168.0.20. How did Windows determine that IP 192.168.0.20 is associated with "mymac.local" since there's no DNS on my network? Is it some broadcast? What protocol is used?