wxSocket on Mac - use of Hostname fails

[David Mathews]

I have all my network code running on the Mac, but it can't call back  
when finished by using the hostname like the PC versions can.
It works if I give it the current ip address, but this changes daily.

Does anyone know how to make a hostname (machine name) work from the  
Mac?
How to enable a Mac to find a machine by its network name rather than  
current ip address?

Thanks,
David