*> *> In the first case I describe in this message, I wonder why the lowest address *> of class E is not 240.0.0.1 because the adress with all 1 and all 0 have *> special meanings (all 0 means "this" and all "1" means broadcast). *> Because the internal structure and semantics of a class E address are totally undefined. Maybe the low order bits are NOT a host address, for example. Note that class D addresses were reserved for many years, until IP multicast was invented around 1988 and assigned to class D. Then class E became reserved. If/when we find a use of class E addresses, presumably class F will become reserved. Bob Braden *> Thank you very much, *> Mai Trang *>