Sharpe, Sam J wrote: > 2009/6/8 gmspro <gmspro at yahoo.com>: >> >> 1.Why most of the addresses in class A are wasted? >> 2.How the block of class C addresses are calculated? > > Your questions make no sense. You will need to expand on them. These sound like homework questions the OP's asking us to answer to avoid doing the research. Kevin Kofler