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
18.21.2.1 0:0:0:0:0:ffff:1215:201
18.21.2.2 0:0:0:0:0:ffff:1215:202
18.21.2.3 0:0:0:0:0:ffff:1215:203
18.21.2.4 0:0:0:0:0:ffff:1215:204
18.21.2.5 0:0:0:0:0:ffff:1215:205
18.21.2.6 0:0:0:0:0:ffff:1215:206
18.21.2.7 0:0:0:0:0:ffff:1215:207
18.21.2.8 0:0:0:0:0:ffff:1215:208
18.21.2.9 0:0:0:0:0:ffff:1215:209
18.21.2.10 0:0:0:0:0:ffff:1215:20a
18.21.2.11 0:0:0:0:0:ffff:1215:20b
18.21.2.12 0:0:0:0:0:ffff:1215:20c
18.21.2.13 0:0:0:0:0:ffff:1215:20d
18.21.2.14 0:0:0:0:0:ffff:1215:20e
18.21.2.15 0:0:0:0:0:ffff:1215:20f
18.21.2.16 0:0:0:0:0:ffff:1215:210
18.21.2.17 0:0:0:0:0:ffff:1215:211
18.21.2.18 0:0:0:0:0:ffff:1215:212
18.21.2.19 0:0:0:0:0:ffff:1215:213
18.21.2.20 0:0:0:0:0:ffff:1215:214
18.21.2.21 0:0:0:0:0:ffff:1215:215
18.21.2.22 0:0:0:0:0:ffff:1215:216
18.21.2.23 0:0:0:0:0:ffff:1215:217
18.21.2.24 0:0:0:0:0:ffff:1215:218
18.21.2.25 0:0:0:0:0:ffff:1215:219
18.21.2.26 0:0:0:0:0:ffff:1215:21a
18.21.2.27 0:0:0:0:0:ffff:1215:21b
18.21.2.28 0:0:0:0:0:ffff:1215:21c
18.21.2.29 0:0:0:0:0:ffff:1215:21d
18.21.2.30 0:0:0:0:0:ffff:1215:21e
18.21.2.31 0:0:0:0:0:ffff:1215:21f
18.21.2.32 0:0:0:0:0:ffff:1215:220
18.21.2.33 0:0:0:0:0:ffff:1215:221
18.21.2.34 0:0:0:0:0:ffff:1215:222
18.21.2.35 0:0:0:0:0:ffff:1215:223
18.21.2.36 0:0:0:0:0:ffff:1215:224
18.21.2.37 0:0:0:0:0:ffff:1215:225
18.21.2.38 0:0:0:0:0:ffff:1215:226
18.21.2.39 0:0:0:0:0:ffff:1215:227
18.21.2.40 0:0:0:0:0:ffff:1215:228
18.21.2.41 0:0:0:0:0:ffff:1215:229
18.21.2.42 0:0:0:0:0:ffff:1215:22a
18.21.2.43 0:0:0:0:0:ffff:1215:22b
18.21.2.44 0:0:0:0:0:ffff:1215:22c
18.21.2.45 0:0:0:0:0:ffff:1215:22d
18.21.2.46 0:0:0:0:0:ffff:1215:22e
18.21.2.47 0:0:0:0:0:ffff:1215:22f
18.21.2.48 0:0:0:0:0:ffff:1215:230
18.21.2.49 0:0:0:0:0:ffff:1215:231
18.21.2.50 0:0:0:0:0:ffff:1215:232
18.21.2.51 0:0:0:0:0:ffff:1215:233
18.21.2.52 0:0:0:0:0:ffff:1215:234
18.21.2.53 0:0:0:0:0:ffff:1215:235
18.21.2.54 0:0:0:0:0:ffff:1215:236
18.21.2.55 0:0:0:0:0:ffff:1215:237
18.21.2.56 0:0:0:0:0:ffff:1215:238
18.21.2.57 0:0:0:0:0:ffff:1215:239
18.21.2.58 0:0:0:0:0:ffff:1215:23a
18.21.2.59 0:0:0:0:0:ffff:1215:23b
18.21.2.60 0:0:0:0:0:ffff:1215:23c


18.21.2.61 0:0:0:0:0:ffff:1215:23d
18.21.2.62 0:0:0:0:0:ffff:1215:23e
18.21.2.63 0:0:0:0:0:ffff:1215:23f
18.21.2.64 0:0:0:0:0:ffff:1215:240
18.21.2.65 0:0:0:0:0:ffff:1215:241
18.21.2.66 0:0:0:0:0:ffff:1215:242
18.21.2.67 0:0:0:0:0:ffff:1215:243
18.21.2.68 0:0:0:0:0:ffff:1215:244
18.21.2.69 0:0:0:0:0:ffff:1215:245
18.21.2.70 0:0:0:0:0:ffff:1215:246
18.21.2.71 0:0:0:0:0:ffff:1215:247
18.21.2.72 0:0:0:0:0:ffff:1215:248
18.21.2.73 0:0:0:0:0:ffff:1215:249
18.21.2.74 0:0:0:0:0:ffff:1215:24a
18.21.2.75 0:0:0:0:0:ffff:1215:24b
18.21.2.76 0:0:0:0:0:ffff:1215:24c
18.21.2.77 0:0:0:0:0:ffff:1215:24d
18.21.2.78 0:0:0:0:0:ffff:1215:24e
18.21.2.79 0:0:0:0:0:ffff:1215:24f
18.21.2.80 0:0:0:0:0:ffff:1215:250
18.21.2.81 0:0:0:0:0:ffff:1215:251
18.21.2.82 0:0:0:0:0:ffff:1215:252
18.21.2.83 0:0:0:0:0:ffff:1215:253
18.21.2.84 0:0:0:0:0:ffff:1215:254
18.21.2.85 0:0:0:0:0:ffff:1215:255
18.21.2.86 0:0:0:0:0:ffff:1215:256
18.21.2.87 0:0:0:0:0:ffff:1215:257
18.21.2.88 0:0:0:0:0:ffff:1215:258
18.21.2.89 0:0:0:0:0:ffff:1215:259
18.21.2.90 0:0:0:0:0:ffff:1215:25a
18.21.2.91 0:0:0:0:0:ffff:1215:25b
18.21.2.92 0:0:0:0:0:ffff:1215:25c
18.21.2.93 0:0:0:0:0:ffff:1215:25d
18.21.2.94 0:0:0:0:0:ffff:1215:25e
18.21.2.95 0:0:0:0:0:ffff:1215:25f
18.21.2.96 0:0:0:0:0:ffff:1215:260
18.21.2.97 0:0:0:0:0:ffff:1215:261
18.21.2.98 0:0:0:0:0:ffff:1215:262
18.21.2.99 0:0:0:0:0:ffff:1215:263
18.21.2.100 0:0:0:0:0:ffff:1215:264
18.21.2.101 0:0:0:0:0:ffff:1215:265
18.21.2.102 0:0:0:0:0:ffff:1215:266
18.21.2.103 0:0:0:0:0:ffff:1215:267
18.21.2.104 0:0:0:0:0:ffff:1215:268
18.21.2.105 0:0:0:0:0:ffff:1215:269
18.21.2.106 0:0:0:0:0:ffff:1215:26a
18.21.2.107 0:0:0:0:0:ffff:1215:26b
18.21.2.108 0:0:0:0:0:ffff:1215:26c
18.21.2.109 0:0:0:0:0:ffff:1215:26d
18.21.2.110 0:0:0:0:0:ffff:1215:26e
18.21.2.111 0:0:0:0:0:ffff:1215:26f
18.21.2.112 0:0:0:0:0:ffff:1215:270
18.21.2.113 0:0:0:0:0:ffff:1215:271
18.21.2.114 0:0:0:0:0:ffff:1215:272
18.21.2.115 0:0:0:0:0:ffff:1215:273
18.21.2.116 0:0:0:0:0:ffff:1215:274
18.21.2.117 0:0:0:0:0:ffff:1215:275
18.21.2.118 0:0:0:0:0:ffff:1215:276
18.21.2.119 0:0:0:0:0:ffff:1215:277
18.21.2.120 0:0:0:0:0:ffff:1215:278


18.21.2.121 0:0:0:0:0:ffff:1215:279
18.21.2.122 0:0:0:0:0:ffff:1215:27a
18.21.2.123 0:0:0:0:0:ffff:1215:27b
18.21.2.124 0:0:0:0:0:ffff:1215:27c
18.21.2.125 0:0:0:0:0:ffff:1215:27d
18.21.2.126 0:0:0:0:0:ffff:1215:27e
18.21.2.127 0:0:0:0:0:ffff:1215:27f
18.21.2.128 0:0:0:0:0:ffff:1215:280
18.21.2.129 0:0:0:0:0:ffff:1215:281
18.21.2.130 0:0:0:0:0:ffff:1215:282
18.21.2.131 0:0:0:0:0:ffff:1215:283
18.21.2.132 0:0:0:0:0:ffff:1215:284
18.21.2.133 0:0:0:0:0:ffff:1215:285
18.21.2.134 0:0:0:0:0:ffff:1215:286
18.21.2.135 0:0:0:0:0:ffff:1215:287
18.21.2.136 0:0:0:0:0:ffff:1215:288
18.21.2.137 0:0:0:0:0:ffff:1215:289
18.21.2.138 0:0:0:0:0:ffff:1215:28a
18.21.2.139 0:0:0:0:0:ffff:1215:28b
18.21.2.140 0:0:0:0:0:ffff:1215:28c
18.21.2.141 0:0:0:0:0:ffff:1215:28d
18.21.2.142 0:0:0:0:0:ffff:1215:28e
18.21.2.143 0:0:0:0:0:ffff:1215:28f
18.21.2.144 0:0:0:0:0:ffff:1215:290
18.21.2.145 0:0:0:0:0:ffff:1215:291
18.21.2.146 0:0:0:0:0:ffff:1215:292
18.21.2.147 0:0:0:0:0:ffff:1215:293
18.21.2.148 0:0:0:0:0:ffff:1215:294
18.21.2.149 0:0:0:0:0:ffff:1215:295
18.21.2.150 0:0:0:0:0:ffff:1215:296
18.21.2.151 0:0:0:0:0:ffff:1215:297
18.21.2.152 0:0:0:0:0:ffff:1215:298
18.21.2.153 0:0:0:0:0:ffff:1215:299
18.21.2.154 0:0:0:0:0:ffff:1215:29a
18.21.2.155 0:0:0:0:0:ffff:1215:29b
18.21.2.156 0:0:0:0:0:ffff:1215:29c
18.21.2.157 0:0:0:0:0:ffff:1215:29d
18.21.2.158 0:0:0:0:0:ffff:1215:29e
18.21.2.159 0:0:0:0:0:ffff:1215:29f
18.21.2.160 0:0:0:0:0:ffff:1215:2a0
18.21.2.161 0:0:0:0:0:ffff:1215:2a1
18.21.2.162 0:0:0:0:0:ffff:1215:2a2
18.21.2.163 0:0:0:0:0:ffff:1215:2a3
18.21.2.164 0:0:0:0:0:ffff:1215:2a4
18.21.2.165 0:0:0:0:0:ffff:1215:2a5
18.21.2.166 0:0:0:0:0:ffff:1215:2a6
18.21.2.167 0:0:0:0:0:ffff:1215:2a7
18.21.2.168 0:0:0:0:0:ffff:1215:2a8
18.21.2.169 0:0:0:0:0:ffff:1215:2a9
18.21.2.170 0:0:0:0:0:ffff:1215:2aa
18.21.2.171 0:0:0:0:0:ffff:1215:2ab
18.21.2.172 0:0:0:0:0:ffff:1215:2ac
18.21.2.173 0:0:0:0:0:ffff:1215:2ad
18.21.2.174 0:0:0:0:0:ffff:1215:2ae
18.21.2.175 0:0:0:0:0:ffff:1215:2af
18.21.2.176 0:0:0:0:0:ffff:1215:2b0
18.21.2.177 0:0:0:0:0:ffff:1215:2b1
18.21.2.178 0:0:0:0:0:ffff:1215:2b2
18.21.2.179 0:0:0:0:0:ffff:1215:2b3
18.21.2.180 0:0:0:0:0:ffff:1215:2b4


18.21.2.181 0:0:0:0:0:ffff:1215:2b5
18.21.2.182 0:0:0:0:0:ffff:1215:2b6
18.21.2.183 0:0:0:0:0:ffff:1215:2b7
18.21.2.184 0:0:0:0:0:ffff:1215:2b8
18.21.2.185 0:0:0:0:0:ffff:1215:2b9
18.21.2.186 0:0:0:0:0:ffff:1215:2ba
18.21.2.187 0:0:0:0:0:ffff:1215:2bb
18.21.2.188 0:0:0:0:0:ffff:1215:2bc
18.21.2.189 0:0:0:0:0:ffff:1215:2bd
18.21.2.190 0:0:0:0:0:ffff:1215:2be
18.21.2.191 0:0:0:0:0:ffff:1215:2bf
18.21.2.192 0:0:0:0:0:ffff:1215:2c0
18.21.2.193 0:0:0:0:0:ffff:1215:2c1
18.21.2.194 0:0:0:0:0:ffff:1215:2c2
18.21.2.195 0:0:0:0:0:ffff:1215:2c3
18.21.2.196 0:0:0:0:0:ffff:1215:2c4
18.21.2.197 0:0:0:0:0:ffff:1215:2c5
18.21.2.198 0:0:0:0:0:ffff:1215:2c6
18.21.2.199 0:0:0:0:0:ffff:1215:2c7
18.21.2.200 0:0:0:0:0:ffff:1215:2c8
18.21.2.201 0:0:0:0:0:ffff:1215:2c9
18.21.2.202 0:0:0:0:0:ffff:1215:2ca
18.21.2.203 0:0:0:0:0:ffff:1215:2cb
18.21.2.204 0:0:0:0:0:ffff:1215:2cc
18.21.2.205 0:0:0:0:0:ffff:1215:2cd
18.21.2.206 0:0:0:0:0:ffff:1215:2ce
18.21.2.207 0:0:0:0:0:ffff:1215:2cf
18.21.2.208 0:0:0:0:0:ffff:1215:2d0
18.21.2.209 0:0:0:0:0:ffff:1215:2d1
18.21.2.210 0:0:0:0:0:ffff:1215:2d2
18.21.2.211 0:0:0:0:0:ffff:1215:2d3
18.21.2.212 0:0:0:0:0:ffff:1215:2d4
18.21.2.213 0:0:0:0:0:ffff:1215:2d5
18.21.2.214 0:0:0:0:0:ffff:1215:2d6
18.21.2.215 0:0:0:0:0:ffff:1215:2d7
18.21.2.216 0:0:0:0:0:ffff:1215:2d8
18.21.2.217 0:0:0:0:0:ffff:1215:2d9
18.21.2.218 0:0:0:0:0:ffff:1215:2da
18.21.2.219 0:0:0:0:0:ffff:1215:2db
18.21.2.220 0:0:0:0:0:ffff:1215:2dc
18.21.2.221 0:0:0:0:0:ffff:1215:2dd
18.21.2.222 0:0:0:0:0:ffff:1215:2de
18.21.2.223 0:0:0:0:0:ffff:1215:2df
18.21.2.224 0:0:0:0:0:ffff:1215:2e0
18.21.2.225 0:0:0:0:0:ffff:1215:2e1
18.21.2.226 0:0:0:0:0:ffff:1215:2e2
18.21.2.227 0:0:0:0:0:ffff:1215:2e3
18.21.2.228 0:0:0:0:0:ffff:1215:2e4
18.21.2.229 0:0:0:0:0:ffff:1215:2e5
18.21.2.230 0:0:0:0:0:ffff:1215:2e6
18.21.2.231 0:0:0:0:0:ffff:1215:2e7
18.21.2.232 0:0:0:0:0:ffff:1215:2e8
18.21.2.233 0:0:0:0:0:ffff:1215:2e9
18.21.2.234 0:0:0:0:0:ffff:1215:2ea
18.21.2.235 0:0:0:0:0:ffff:1215:2eb
18.21.2.236 0:0:0:0:0:ffff:1215:2ec
18.21.2.237 0:0:0:0:0:ffff:1215:2ed
18.21.2.238 0:0:0:0:0:ffff:1215:2ee
18.21.2.239 0:0:0:0:0:ffff:1215:2ef
18.21.2.240 0:0:0:0:0:ffff:1215:2f0
18.21.2.241 0:0:0:0:0:ffff:1215:2f1
18.21.2.242 0:0:0:0:0:ffff:1215:2f2
18.21.2.243 0:0:0:0:0:ffff:1215:2f3
18.21.2.244 0:0:0:0:0:ffff:1215:2f4
18.21.2.245 0:0:0:0:0:ffff:1215:2f5
18.21.2.246 0:0:0:0:0:ffff:1215:2f6
18.21.2.247 0:0:0:0:0:ffff:1215:2f7
18.21.2.248 0:0:0:0:0:ffff:1215:2f8
18.21.2.249 0:0:0:0:0:ffff:1215:2f9
18.21.2.250 0:0:0:0:0:ffff:1215:2fa
18.21.2.251 0:0:0:0:0:ffff:1215:2fb
18.21.2.252 0:0:0:0:0:ffff:1215:2fc
18.21.2.253 0:0:0:0:0:ffff:1215:2fd
18.21.2.254 0:0:0:0:0:ffff:1215:2fe
18.21.2.255 0:0:0:0:0:ffff:1215:2ff


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.