On Tue, 2002-07-16 at 10:57, Vidiot wrote: > >I have been reading, or rather refreshing, my memory on IP addressing and > >subnets. My question is best presented with an example. Suppose a LAN is > >assigned an address block: 192.168.1.0 / 255.255.255.0. Why is the first > >available host address 192.168.1.1 instead of 192.168.1.0? Most books will > >just say that 192.168.1.0 is the network address of the LAN. But I don't see > >any confusion arising when this address is assigned to a host. Perhaps > >someone can shed some light on this. > >David Chao > > The .0 and .255 are special addresses (broadcast, etc.) and cannot be assigned. > You really only have .1 -> .254 to use.
Technically, there's nothing "special" about .0 and .255. IP addresses can not be assigned to the first or last number in a subnet. In a class C, that's .0 and .255. However, in networks with netmasks of fewer than 24 bits, some .0 and .255 addresses are usable. In the subnets 192.168.1.0/25 and 192.168.1.128/25, the addresses 192.168.1.0 and 192.168.1.128 are the network addresses, and 192.168.1.127 and 192.168.1.255 re the broadcast addresses of each network, respectively. All four of these addresses are unusable by hosts in the subnets as interface addresses. Thus, the more you subnet, the fewer numbers you have available. _______________________________________________ Redhat-list mailing list [EMAIL PROTECTED] https://listman.redhat.com/mailman/listinfo/redhat-list
