Find IP IPv4 Network/Subnet and its host address ranges

What is an IPv4 IP address its network and host address ranges?

An IPv4 IP address is an address used in order to uniquely identify a device on an IP network. The address is made up of 32 binary bits, which can be divisible into a network portion and host portion with the help of a subnet mask. The 32 binary bits are broken into four octets (1 octet = 8 bits). Each octet is converted to decimal and separated by a period (dot).

How to Subnet IPv4? Its simple answer is that subnetting is the process of taking a network and splitting it into smaller networks, known as subnets. It's used to free up more public IPv4 addresses and segment networks for security and easier management.
Following are the ranges of IPv4 subnet/network address and their host addresses.

IPv4 AddressIPv6 Address
100.21.15.1 0:0:0:0:0:ffff:6415:f01
100.21.15.2 0:0:0:0:0:ffff:6415:f02
100.21.15.3 0:0:0:0:0:ffff:6415:f03
100.21.15.4 0:0:0:0:0:ffff:6415:f04
100.21.15.5 0:0:0:0:0:ffff:6415:f05
100.21.15.6 0:0:0:0:0:ffff:6415:f06
100.21.15.7 0:0:0:0:0:ffff:6415:f07
100.21.15.8 0:0:0:0:0:ffff:6415:f08
100.21.15.9 0:0:0:0:0:ffff:6415:f09
100.21.15.10 0:0:0:0:0:ffff:6415:f0a
100.21.15.11 0:0:0:0:0:ffff:6415:f0b
100.21.15.12 0:0:0:0:0:ffff:6415:f0c
100.21.15.13 0:0:0:0:0:ffff:6415:f0d
100.21.15.14 0:0:0:0:0:ffff:6415:f0e
100.21.15.15 0:0:0:0:0:ffff:6415:f0f
100.21.15.16 0:0:0:0:0:ffff:6415:f10
100.21.15.17 0:0:0:0:0:ffff:6415:f11
100.21.15.18 0:0:0:0:0:ffff:6415:f12
100.21.15.19 0:0:0:0:0:ffff:6415:f13
100.21.15.20 0:0:0:0:0:ffff:6415:f14
100.21.15.21 0:0:0:0:0:ffff:6415:f15
100.21.15.22 0:0:0:0:0:ffff:6415:f16
100.21.15.23 0:0:0:0:0:ffff:6415:f17
100.21.15.24 0:0:0:0:0:ffff:6415:f18
100.21.15.25 0:0:0:0:0:ffff:6415:f19
100.21.15.26 0:0:0:0:0:ffff:6415:f1a
100.21.15.27 0:0:0:0:0:ffff:6415:f1b
100.21.15.28 0:0:0:0:0:ffff:6415:f1c
100.21.15.29 0:0:0:0:0:ffff:6415:f1d
100.21.15.30 0:0:0:0:0:ffff:6415:f1e
100.21.15.31 0:0:0:0:0:ffff:6415:f1f
100.21.15.32 0:0:0:0:0:ffff:6415:f20
100.21.15.33 0:0:0:0:0:ffff:6415:f21
100.21.15.34 0:0:0:0:0:ffff:6415:f22
100.21.15.35 0:0:0:0:0:ffff:6415:f23
100.21.15.36 0:0:0:0:0:ffff:6415:f24
100.21.15.37 0:0:0:0:0:ffff:6415:f25
100.21.15.38 0:0:0:0:0:ffff:6415:f26
100.21.15.39 0:0:0:0:0:ffff:6415:f27
100.21.15.40 0:0:0:0:0:ffff:6415:f28
100.21.15.41 0:0:0:0:0:ffff:6415:f29
100.21.15.42 0:0:0:0:0:ffff:6415:f2a
100.21.15.43 0:0:0:0:0:ffff:6415:f2b
100.21.15.44 0:0:0:0:0:ffff:6415:f2c
100.21.15.45 0:0:0:0:0:ffff:6415:f2d
100.21.15.46 0:0:0:0:0:ffff:6415:f2e
100.21.15.47 0:0:0:0:0:ffff:6415:f2f
100.21.15.48 0:0:0:0:0:ffff:6415:f30
100.21.15.49 0:0:0:0:0:ffff:6415:f31
100.21.15.50 0:0:0:0:0:ffff:6415:f32
100.21.15.51 0:0:0:0:0:ffff:6415:f33
100.21.15.52 0:0:0:0:0:ffff:6415:f34
100.21.15.53 0:0:0:0:0:ffff:6415:f35
100.21.15.54 0:0:0:0:0:ffff:6415:f36
100.21.15.55 0:0:0:0:0:ffff:6415:f37
100.21.15.56 0:0:0:0:0:ffff:6415:f38
100.21.15.57 0:0:0:0:0:ffff:6415:f39
100.21.15.58 0:0:0:0:0:ffff:6415:f3a
100.21.15.59 0:0:0:0:0:ffff:6415:f3b
100.21.15.60 0:0:0:0:0:ffff:6415:f3c


100.21.15.61 0:0:0:0:0:ffff:6415:f3d
100.21.15.62 0:0:0:0:0:ffff:6415:f3e
100.21.15.63 0:0:0:0:0:ffff:6415:f3f
100.21.15.64 0:0:0:0:0:ffff:6415:f40
100.21.15.65 0:0:0:0:0:ffff:6415:f41
100.21.15.66 0:0:0:0:0:ffff:6415:f42
100.21.15.67 0:0:0:0:0:ffff:6415:f43
100.21.15.68 0:0:0:0:0:ffff:6415:f44
100.21.15.69 0:0:0:0:0:ffff:6415:f45
100.21.15.70 0:0:0:0:0:ffff:6415:f46
100.21.15.71 0:0:0:0:0:ffff:6415:f47
100.21.15.72 0:0:0:0:0:ffff:6415:f48
100.21.15.73 0:0:0:0:0:ffff:6415:f49
100.21.15.74 0:0:0:0:0:ffff:6415:f4a
100.21.15.75 0:0:0:0:0:ffff:6415:f4b
100.21.15.76 0:0:0:0:0:ffff:6415:f4c
100.21.15.77 0:0:0:0:0:ffff:6415:f4d
100.21.15.78 0:0:0:0:0:ffff:6415:f4e
100.21.15.79 0:0:0:0:0:ffff:6415:f4f
100.21.15.80 0:0:0:0:0:ffff:6415:f50
100.21.15.81 0:0:0:0:0:ffff:6415:f51
100.21.15.82 0:0:0:0:0:ffff:6415:f52
100.21.15.83 0:0:0:0:0:ffff:6415:f53
100.21.15.84 0:0:0:0:0:ffff:6415:f54
100.21.15.85 0:0:0:0:0:ffff:6415:f55
100.21.15.86 0:0:0:0:0:ffff:6415:f56
100.21.15.87 0:0:0:0:0:ffff:6415:f57
100.21.15.88 0:0:0:0:0:ffff:6415:f58
100.21.15.89 0:0:0:0:0:ffff:6415:f59
100.21.15.90 0:0:0:0:0:ffff:6415:f5a
100.21.15.91 0:0:0:0:0:ffff:6415:f5b
100.21.15.92 0:0:0:0:0:ffff:6415:f5c
100.21.15.93 0:0:0:0:0:ffff:6415:f5d
100.21.15.94 0:0:0:0:0:ffff:6415:f5e
100.21.15.95 0:0:0:0:0:ffff:6415:f5f
100.21.15.96 0:0:0:0:0:ffff:6415:f60
100.21.15.97 0:0:0:0:0:ffff:6415:f61
100.21.15.98 0:0:0:0:0:ffff:6415:f62
100.21.15.99 0:0:0:0:0:ffff:6415:f63
100.21.15.100 0:0:0:0:0:ffff:6415:f64
100.21.15.101 0:0:0:0:0:ffff:6415:f65
100.21.15.102 0:0:0:0:0:ffff:6415:f66
100.21.15.103 0:0:0:0:0:ffff:6415:f67
100.21.15.104 0:0:0:0:0:ffff:6415:f68
100.21.15.105 0:0:0:0:0:ffff:6415:f69
100.21.15.106 0:0:0:0:0:ffff:6415:f6a
100.21.15.107 0:0:0:0:0:ffff:6415:f6b
100.21.15.108 0:0:0:0:0:ffff:6415:f6c
100.21.15.109 0:0:0:0:0:ffff:6415:f6d
100.21.15.110 0:0:0:0:0:ffff:6415:f6e
100.21.15.111 0:0:0:0:0:ffff:6415:f6f
100.21.15.112 0:0:0:0:0:ffff:6415:f70
100.21.15.113 0:0:0:0:0:ffff:6415:f71
100.21.15.114 0:0:0:0:0:ffff:6415:f72
100.21.15.115 0:0:0:0:0:ffff:6415:f73
100.21.15.116 0:0:0:0:0:ffff:6415:f74
100.21.15.117 0:0:0:0:0:ffff:6415:f75
100.21.15.118 0:0:0:0:0:ffff:6415:f76
100.21.15.119 0:0:0:0:0:ffff:6415:f77
100.21.15.120 0:0:0:0:0:ffff:6415:f78


100.21.15.121 0:0:0:0:0:ffff:6415:f79
100.21.15.122 0:0:0:0:0:ffff:6415:f7a
100.21.15.123 0:0:0:0:0:ffff:6415:f7b
100.21.15.124 0:0:0:0:0:ffff:6415:f7c
100.21.15.125 0:0:0:0:0:ffff:6415:f7d
100.21.15.126 0:0:0:0:0:ffff:6415:f7e
100.21.15.127 0:0:0:0:0:ffff:6415:f7f
100.21.15.128 0:0:0:0:0:ffff:6415:f80
100.21.15.129 0:0:0:0:0:ffff:6415:f81
100.21.15.130 0:0:0:0:0:ffff:6415:f82
100.21.15.131 0:0:0:0:0:ffff:6415:f83
100.21.15.132 0:0:0:0:0:ffff:6415:f84
100.21.15.133 0:0:0:0:0:ffff:6415:f85
100.21.15.134 0:0:0:0:0:ffff:6415:f86
100.21.15.135 0:0:0:0:0:ffff:6415:f87
100.21.15.136 0:0:0:0:0:ffff:6415:f88
100.21.15.137 0:0:0:0:0:ffff:6415:f89
100.21.15.138 0:0:0:0:0:ffff:6415:f8a
100.21.15.139 0:0:0:0:0:ffff:6415:f8b
100.21.15.140 0:0:0:0:0:ffff:6415:f8c
100.21.15.141 0:0:0:0:0:ffff:6415:f8d
100.21.15.142 0:0:0:0:0:ffff:6415:f8e
100.21.15.143 0:0:0:0:0:ffff:6415:f8f
100.21.15.144 0:0:0:0:0:ffff:6415:f90
100.21.15.145 0:0:0:0:0:ffff:6415:f91
100.21.15.146 0:0:0:0:0:ffff:6415:f92
100.21.15.147 0:0:0:0:0:ffff:6415:f93
100.21.15.148 0:0:0:0:0:ffff:6415:f94
100.21.15.149 0:0:0:0:0:ffff:6415:f95
100.21.15.150 0:0:0:0:0:ffff:6415:f96
100.21.15.151 0:0:0:0:0:ffff:6415:f97
100.21.15.152 0:0:0:0:0:ffff:6415:f98
100.21.15.153 0:0:0:0:0:ffff:6415:f99
100.21.15.154 0:0:0:0:0:ffff:6415:f9a
100.21.15.155 0:0:0:0:0:ffff:6415:f9b
100.21.15.156 0:0:0:0:0:ffff:6415:f9c
100.21.15.157 0:0:0:0:0:ffff:6415:f9d
100.21.15.158 0:0:0:0:0:ffff:6415:f9e
100.21.15.159 0:0:0:0:0:ffff:6415:f9f
100.21.15.160 0:0:0:0:0:ffff:6415:fa0
100.21.15.161 0:0:0:0:0:ffff:6415:fa1
100.21.15.162 0:0:0:0:0:ffff:6415:fa2
100.21.15.163 0:0:0:0:0:ffff:6415:fa3
100.21.15.164 0:0:0:0:0:ffff:6415:fa4
100.21.15.165 0:0:0:0:0:ffff:6415:fa5
100.21.15.166 0:0:0:0:0:ffff:6415:fa6
100.21.15.167 0:0:0:0:0:ffff:6415:fa7
100.21.15.168 0:0:0:0:0:ffff:6415:fa8
100.21.15.169 0:0:0:0:0:ffff:6415:fa9
100.21.15.170 0:0:0:0:0:ffff:6415:faa
100.21.15.171 0:0:0:0:0:ffff:6415:fab
100.21.15.172 0:0:0:0:0:ffff:6415:fac
100.21.15.173 0:0:0:0:0:ffff:6415:fad
100.21.15.174 0:0:0:0:0:ffff:6415:fae
100.21.15.175 0:0:0:0:0:ffff:6415:faf
100.21.15.176 0:0:0:0:0:ffff:6415:fb0
100.21.15.177 0:0:0:0:0:ffff:6415:fb1
100.21.15.178 0:0:0:0:0:ffff:6415:fb2
100.21.15.179 0:0:0:0:0:ffff:6415:fb3
100.21.15.180 0:0:0:0:0:ffff:6415:fb4


100.21.15.181 0:0:0:0:0:ffff:6415:fb5
100.21.15.182 0:0:0:0:0:ffff:6415:fb6
100.21.15.183 0:0:0:0:0:ffff:6415:fb7
100.21.15.184 0:0:0:0:0:ffff:6415:fb8
100.21.15.185 0:0:0:0:0:ffff:6415:fb9
100.21.15.186 0:0:0:0:0:ffff:6415:fba
100.21.15.187 0:0:0:0:0:ffff:6415:fbb
100.21.15.188 0:0:0:0:0:ffff:6415:fbc
100.21.15.189 0:0:0:0:0:ffff:6415:fbd
100.21.15.190 0:0:0:0:0:ffff:6415:fbe
100.21.15.191 0:0:0:0:0:ffff:6415:fbf
100.21.15.192 0:0:0:0:0:ffff:6415:fc0
100.21.15.193 0:0:0:0:0:ffff:6415:fc1
100.21.15.194 0:0:0:0:0:ffff:6415:fc2
100.21.15.195 0:0:0:0:0:ffff:6415:fc3
100.21.15.196 0:0:0:0:0:ffff:6415:fc4
100.21.15.197 0:0:0:0:0:ffff:6415:fc5
100.21.15.198 0:0:0:0:0:ffff:6415:fc6
100.21.15.199 0:0:0:0:0:ffff:6415:fc7
100.21.15.200 0:0:0:0:0:ffff:6415:fc8
100.21.15.201 0:0:0:0:0:ffff:6415:fc9
100.21.15.202 0:0:0:0:0:ffff:6415:fca
100.21.15.203 0:0:0:0:0:ffff:6415:fcb
100.21.15.204 0:0:0:0:0:ffff:6415:fcc
100.21.15.205 0:0:0:0:0:ffff:6415:fcd
100.21.15.206 0:0:0:0:0:ffff:6415:fce
100.21.15.207 0:0:0:0:0:ffff:6415:fcf
100.21.15.208 0:0:0:0:0:ffff:6415:fd0
100.21.15.209 0:0:0:0:0:ffff:6415:fd1
100.21.15.210 0:0:0:0:0:ffff:6415:fd2
100.21.15.211 0:0:0:0:0:ffff:6415:fd3
100.21.15.212 0:0:0:0:0:ffff:6415:fd4
100.21.15.213 0:0:0:0:0:ffff:6415:fd5
100.21.15.214 0:0:0:0:0:ffff:6415:fd6
100.21.15.215 0:0:0:0:0:ffff:6415:fd7
100.21.15.216 0:0:0:0:0:ffff:6415:fd8
100.21.15.217 0:0:0:0:0:ffff:6415:fd9
100.21.15.218 0:0:0:0:0:ffff:6415:fda
100.21.15.219 0:0:0:0:0:ffff:6415:fdb
100.21.15.220 0:0:0:0:0:ffff:6415:fdc
100.21.15.221 0:0:0:0:0:ffff:6415:fdd
100.21.15.222 0:0:0:0:0:ffff:6415:fde
100.21.15.223 0:0:0:0:0:ffff:6415:fdf
100.21.15.224 0:0:0:0:0:ffff:6415:fe0
100.21.15.225 0:0:0:0:0:ffff:6415:fe1
100.21.15.226 0:0:0:0:0:ffff:6415:fe2
100.21.15.227 0:0:0:0:0:ffff:6415:fe3
100.21.15.228 0:0:0:0:0:ffff:6415:fe4
100.21.15.229 0:0:0:0:0:ffff:6415:fe5
100.21.15.230 0:0:0:0:0:ffff:6415:fe6
100.21.15.231 0:0:0:0:0:ffff:6415:fe7
100.21.15.232 0:0:0:0:0:ffff:6415:fe8
100.21.15.233 0:0:0:0:0:ffff:6415:fe9
100.21.15.234 0:0:0:0:0:ffff:6415:fea
100.21.15.235 0:0:0:0:0:ffff:6415:feb
100.21.15.236 0:0:0:0:0:ffff:6415:fec
100.21.15.237 0:0:0:0:0:ffff:6415:fed
100.21.15.238 0:0:0:0:0:ffff:6415:fee
100.21.15.239 0:0:0:0:0:ffff:6415:fef
100.21.15.240 0:0:0:0:0:ffff:6415:ff0
100.21.15.241 0:0:0:0:0:ffff:6415:ff1
100.21.15.242 0:0:0:0:0:ffff:6415:ff2
100.21.15.243 0:0:0:0:0:ffff:6415:ff3
100.21.15.244 0:0:0:0:0:ffff:6415:ff4
100.21.15.245 0:0:0:0:0:ffff:6415:ff5
100.21.15.246 0:0:0:0:0:ffff:6415:ff6
100.21.15.247 0:0:0:0:0:ffff:6415:ff7
100.21.15.248 0:0:0:0:0:ffff:6415:ff8
100.21.15.249 0:0:0:0:0:ffff:6415:ff9
100.21.15.250 0:0:0:0:0:ffff:6415:ffa
100.21.15.251 0:0:0:0:0:ffff:6415:ffb
100.21.15.252 0:0:0:0:0:ffff:6415:ffc
100.21.15.253 0:0:0:0:0:ffff:6415:ffd
100.21.15.254 0:0:0:0:0:ffff:6415:ffe
100.21.15.255 0:0:0:0:0:ffff:6415:fff


How we got IPv4 subnet masks?

An IPv4 subnet mask consists of 32 bits; it is a sequence of ones (1) followed by a block of zeros (0). The ones indicate bits in the address used for the network prefix and the trailing block of zeros designates that part as being the host identifier.