Some IPv4 Address Issues

Subnets

See RFC 1878 'Variable Length Subnet Table For IPv4' for details

Subnet Mask Network ID Bits # of Host Bits # of Hosts in Each Subnet # of Subnets Boundary Addresses
.252 30 2 2 64 .0,.4,.8,.12,.16,.20,.24,.28,.32,.36,.40,.44,.48,.52,.56,.60,.64,.68,.72,.76,
.80,.84,.88,.92,.96,.100,.104,.108,.112,.116,.120,.124,.128,.132,.136,
.140,.144,.148,.152,.156,.160,.164,.168,.172,.176,.180,.184,.188,.192,
.196,.200,.204,.208,.212,.216,.220,.224,.228,.232,.236,.240,.244,.248,252
.248 29 3 6 32 .0,.8,.16,.24,.32,.40,.48,.56,.64,.72,.80,.88,.96,.104,.112,.120,.128,.136,
.144,.152,.160,.168,.176,.184,.192,.200,.208,.216,.224,.232,.240,.248
.240 28 4 14 16 .0,.16,.32,.48,.64,.80,.96,.112,.128,.144,.160,.176,.192,.208,.224,.240
.224 27 5 30 8 .0,.32,.64,.96,.128,.160,.192,.224
.192 26 6 62 4 .0,.64,.128,.192
.128 25 7 126 2 .0,.128
.0 24 8 254 1 .0

.255 indicates a single host in a network

Private IP Addresses

See RFC 1918 'Address Allocation for Private Internets' for details

Class A 10.0.0.0 to 10.255.255.255
Class B 172.16.0.0 to 172.31.255.255
Class C 192.168.0.0 to 192.168.255.255

IPv6 References