On 25-Aug-08, at 10:24 AM, Arun Khan wrote:
is this a convention or a rule?
It is a rule. In general, the IPv4_number/no_of_bits defines the
network id. The remainder bits define the "no of hosts" possible in
that network. All 0s in "host field" reserved for the network and all
1s in "host field" reserved for broadcast.
For example a.b.c.d/24 defines a 24 bit mask, a.b.c.0 is the
network id
and a.b.c.255 is the broadcast.