Problem with LAN (and difference between "newLan" and "make-lan")

["Luca" <fn214432@flashnet.it>]

Hi,
I'm Luca from Rome.
When I create a new lan (with make-lan or newLan commands) using the Csma/Ca
or Csma/Cd Mac protocol the simulation stops telling "Mac/Csma/Ca  invalid
command". Why??
I know I should use the Mac/802_x protocols, but I need to use the Csma
becouse I have to implement my own Mac protocol and I'd like to derive it
from the Csma one becouse it's more and more simple than 802_x
implementation which instead is very difficult to be modified!
What have I to do to make the make-lan or newLan commands work with the Csma
protocols?
Just another question: what's the difference between the two commands?
Please answer, thanks!

Luca