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
128.158.21.1 0:0:0:0:0:ffff:809e:1501
128.158.21.2 0:0:0:0:0:ffff:809e:1502
128.158.21.3 0:0:0:0:0:ffff:809e:1503
128.158.21.4 0:0:0:0:0:ffff:809e:1504
128.158.21.5 0:0:0:0:0:ffff:809e:1505
128.158.21.6 0:0:0:0:0:ffff:809e:1506
128.158.21.7 0:0:0:0:0:ffff:809e:1507
128.158.21.8 0:0:0:0:0:ffff:809e:1508
128.158.21.9 0:0:0:0:0:ffff:809e:1509
128.158.21.10 0:0:0:0:0:ffff:809e:150a
128.158.21.11 0:0:0:0:0:ffff:809e:150b
128.158.21.12 0:0:0:0:0:ffff:809e:150c
128.158.21.13 0:0:0:0:0:ffff:809e:150d
128.158.21.14 0:0:0:0:0:ffff:809e:150e
128.158.21.15 0:0:0:0:0:ffff:809e:150f
128.158.21.16 0:0:0:0:0:ffff:809e:1510
128.158.21.17 0:0:0:0:0:ffff:809e:1511
128.158.21.18 0:0:0:0:0:ffff:809e:1512
128.158.21.19 0:0:0:0:0:ffff:809e:1513
128.158.21.20 0:0:0:0:0:ffff:809e:1514
128.158.21.21 0:0:0:0:0:ffff:809e:1515
128.158.21.22 0:0:0:0:0:ffff:809e:1516
128.158.21.23 0:0:0:0:0:ffff:809e:1517
128.158.21.24 0:0:0:0:0:ffff:809e:1518
128.158.21.25 0:0:0:0:0:ffff:809e:1519
128.158.21.26 0:0:0:0:0:ffff:809e:151a
128.158.21.27 0:0:0:0:0:ffff:809e:151b
128.158.21.28 0:0:0:0:0:ffff:809e:151c
128.158.21.29 0:0:0:0:0:ffff:809e:151d
128.158.21.30 0:0:0:0:0:ffff:809e:151e
128.158.21.31 0:0:0:0:0:ffff:809e:151f
128.158.21.32 0:0:0:0:0:ffff:809e:1520
128.158.21.33 0:0:0:0:0:ffff:809e:1521
128.158.21.34 0:0:0:0:0:ffff:809e:1522
128.158.21.35 0:0:0:0:0:ffff:809e:1523
128.158.21.36 0:0:0:0:0:ffff:809e:1524
128.158.21.37 0:0:0:0:0:ffff:809e:1525
128.158.21.38 0:0:0:0:0:ffff:809e:1526
128.158.21.39 0:0:0:0:0:ffff:809e:1527
128.158.21.40 0:0:0:0:0:ffff:809e:1528
128.158.21.41 0:0:0:0:0:ffff:809e:1529
128.158.21.42 0:0:0:0:0:ffff:809e:152a
128.158.21.43 0:0:0:0:0:ffff:809e:152b
128.158.21.44 0:0:0:0:0:ffff:809e:152c
128.158.21.45 0:0:0:0:0:ffff:809e:152d
128.158.21.46 0:0:0:0:0:ffff:809e:152e
128.158.21.47 0:0:0:0:0:ffff:809e:152f
128.158.21.48 0:0:0:0:0:ffff:809e:1530
128.158.21.49 0:0:0:0:0:ffff:809e:1531
128.158.21.50 0:0:0:0:0:ffff:809e:1532
128.158.21.51 0:0:0:0:0:ffff:809e:1533
128.158.21.52 0:0:0:0:0:ffff:809e:1534
128.158.21.53 0:0:0:0:0:ffff:809e:1535
128.158.21.54 0:0:0:0:0:ffff:809e:1536
128.158.21.55 0:0:0:0:0:ffff:809e:1537
128.158.21.56 0:0:0:0:0:ffff:809e:1538
128.158.21.57 0:0:0:0:0:ffff:809e:1539
128.158.21.58 0:0:0:0:0:ffff:809e:153a
128.158.21.59 0:0:0:0:0:ffff:809e:153b
128.158.21.60 0:0:0:0:0:ffff:809e:153c


128.158.21.61 0:0:0:0:0:ffff:809e:153d
128.158.21.62 0:0:0:0:0:ffff:809e:153e
128.158.21.63 0:0:0:0:0:ffff:809e:153f
128.158.21.64 0:0:0:0:0:ffff:809e:1540
128.158.21.65 0:0:0:0:0:ffff:809e:1541
128.158.21.66 0:0:0:0:0:ffff:809e:1542
128.158.21.67 0:0:0:0:0:ffff:809e:1543
128.158.21.68 0:0:0:0:0:ffff:809e:1544
128.158.21.69 0:0:0:0:0:ffff:809e:1545
128.158.21.70 0:0:0:0:0:ffff:809e:1546
128.158.21.71 0:0:0:0:0:ffff:809e:1547
128.158.21.72 0:0:0:0:0:ffff:809e:1548
128.158.21.73 0:0:0:0:0:ffff:809e:1549
128.158.21.74 0:0:0:0:0:ffff:809e:154a
128.158.21.75 0:0:0:0:0:ffff:809e:154b
128.158.21.76 0:0:0:0:0:ffff:809e:154c
128.158.21.77 0:0:0:0:0:ffff:809e:154d
128.158.21.78 0:0:0:0:0:ffff:809e:154e
128.158.21.79 0:0:0:0:0:ffff:809e:154f
128.158.21.80 0:0:0:0:0:ffff:809e:1550
128.158.21.81 0:0:0:0:0:ffff:809e:1551
128.158.21.82 0:0:0:0:0:ffff:809e:1552
128.158.21.83 0:0:0:0:0:ffff:809e:1553
128.158.21.84 0:0:0:0:0:ffff:809e:1554
128.158.21.85 0:0:0:0:0:ffff:809e:1555
128.158.21.86 0:0:0:0:0:ffff:809e:1556
128.158.21.87 0:0:0:0:0:ffff:809e:1557
128.158.21.88 0:0:0:0:0:ffff:809e:1558
128.158.21.89 0:0:0:0:0:ffff:809e:1559
128.158.21.90 0:0:0:0:0:ffff:809e:155a
128.158.21.91 0:0:0:0:0:ffff:809e:155b
128.158.21.92 0:0:0:0:0:ffff:809e:155c
128.158.21.93 0:0:0:0:0:ffff:809e:155d
128.158.21.94 0:0:0:0:0:ffff:809e:155e
128.158.21.95 0:0:0:0:0:ffff:809e:155f
128.158.21.96 0:0:0:0:0:ffff:809e:1560
128.158.21.97 0:0:0:0:0:ffff:809e:1561
128.158.21.98 0:0:0:0:0:ffff:809e:1562
128.158.21.99 0:0:0:0:0:ffff:809e:1563
128.158.21.100 0:0:0:0:0:ffff:809e:1564
128.158.21.101 0:0:0:0:0:ffff:809e:1565
128.158.21.102 0:0:0:0:0:ffff:809e:1566
128.158.21.103 0:0:0:0:0:ffff:809e:1567
128.158.21.104 0:0:0:0:0:ffff:809e:1568
128.158.21.105 0:0:0:0:0:ffff:809e:1569
128.158.21.106 0:0:0:0:0:ffff:809e:156a
128.158.21.107 0:0:0:0:0:ffff:809e:156b
128.158.21.108 0:0:0:0:0:ffff:809e:156c
128.158.21.109 0:0:0:0:0:ffff:809e:156d
128.158.21.110 0:0:0:0:0:ffff:809e:156e
128.158.21.111 0:0:0:0:0:ffff:809e:156f
128.158.21.112 0:0:0:0:0:ffff:809e:1570
128.158.21.113 0:0:0:0:0:ffff:809e:1571
128.158.21.114 0:0:0:0:0:ffff:809e:1572
128.158.21.115 0:0:0:0:0:ffff:809e:1573
128.158.21.116 0:0:0:0:0:ffff:809e:1574
128.158.21.117 0:0:0:0:0:ffff:809e:1575
128.158.21.118 0:0:0:0:0:ffff:809e:1576
128.158.21.119 0:0:0:0:0:ffff:809e:1577
128.158.21.120 0:0:0:0:0:ffff:809e:1578


128.158.21.121 0:0:0:0:0:ffff:809e:1579
128.158.21.122 0:0:0:0:0:ffff:809e:157a
128.158.21.123 0:0:0:0:0:ffff:809e:157b
128.158.21.124 0:0:0:0:0:ffff:809e:157c
128.158.21.125 0:0:0:0:0:ffff:809e:157d
128.158.21.126 0:0:0:0:0:ffff:809e:157e
128.158.21.127 0:0:0:0:0:ffff:809e:157f
128.158.21.128 0:0:0:0:0:ffff:809e:1580
128.158.21.129 0:0:0:0:0:ffff:809e:1581
128.158.21.130 0:0:0:0:0:ffff:809e:1582
128.158.21.131 0:0:0:0:0:ffff:809e:1583
128.158.21.132 0:0:0:0:0:ffff:809e:1584
128.158.21.133 0:0:0:0:0:ffff:809e:1585
128.158.21.134 0:0:0:0:0:ffff:809e:1586
128.158.21.135 0:0:0:0:0:ffff:809e:1587
128.158.21.136 0:0:0:0:0:ffff:809e:1588
128.158.21.137 0:0:0:0:0:ffff:809e:1589
128.158.21.138 0:0:0:0:0:ffff:809e:158a
128.158.21.139 0:0:0:0:0:ffff:809e:158b
128.158.21.140 0:0:0:0:0:ffff:809e:158c
128.158.21.141 0:0:0:0:0:ffff:809e:158d
128.158.21.142 0:0:0:0:0:ffff:809e:158e
128.158.21.143 0:0:0:0:0:ffff:809e:158f
128.158.21.144 0:0:0:0:0:ffff:809e:1590
128.158.21.145 0:0:0:0:0:ffff:809e:1591
128.158.21.146 0:0:0:0:0:ffff:809e:1592
128.158.21.147 0:0:0:0:0:ffff:809e:1593
128.158.21.148 0:0:0:0:0:ffff:809e:1594
128.158.21.149 0:0:0:0:0:ffff:809e:1595
128.158.21.150 0:0:0:0:0:ffff:809e:1596
128.158.21.151 0:0:0:0:0:ffff:809e:1597
128.158.21.152 0:0:0:0:0:ffff:809e:1598
128.158.21.153 0:0:0:0:0:ffff:809e:1599
128.158.21.154 0:0:0:0:0:ffff:809e:159a
128.158.21.155 0:0:0:0:0:ffff:809e:159b
128.158.21.156 0:0:0:0:0:ffff:809e:159c
128.158.21.157 0:0:0:0:0:ffff:809e:159d
128.158.21.158 0:0:0:0:0:ffff:809e:159e
128.158.21.159 0:0:0:0:0:ffff:809e:159f
128.158.21.160 0:0:0:0:0:ffff:809e:15a0
128.158.21.161 0:0:0:0:0:ffff:809e:15a1
128.158.21.162 0:0:0:0:0:ffff:809e:15a2
128.158.21.163 0:0:0:0:0:ffff:809e:15a3
128.158.21.164 0:0:0:0:0:ffff:809e:15a4
128.158.21.165 0:0:0:0:0:ffff:809e:15a5
128.158.21.166 0:0:0:0:0:ffff:809e:15a6
128.158.21.167 0:0:0:0:0:ffff:809e:15a7
128.158.21.168 0:0:0:0:0:ffff:809e:15a8
128.158.21.169 0:0:0:0:0:ffff:809e:15a9
128.158.21.170 0:0:0:0:0:ffff:809e:15aa
128.158.21.171 0:0:0:0:0:ffff:809e:15ab
128.158.21.172 0:0:0:0:0:ffff:809e:15ac
128.158.21.173 0:0:0:0:0:ffff:809e:15ad
128.158.21.174 0:0:0:0:0:ffff:809e:15ae
128.158.21.175 0:0:0:0:0:ffff:809e:15af
128.158.21.176 0:0:0:0:0:ffff:809e:15b0
128.158.21.177 0:0:0:0:0:ffff:809e:15b1
128.158.21.178 0:0:0:0:0:ffff:809e:15b2
128.158.21.179 0:0:0:0:0:ffff:809e:15b3
128.158.21.180 0:0:0:0:0:ffff:809e:15b4


128.158.21.181 0:0:0:0:0:ffff:809e:15b5
128.158.21.182 0:0:0:0:0:ffff:809e:15b6
128.158.21.183 0:0:0:0:0:ffff:809e:15b7
128.158.21.184 0:0:0:0:0:ffff:809e:15b8
128.158.21.185 0:0:0:0:0:ffff:809e:15b9
128.158.21.186 0:0:0:0:0:ffff:809e:15ba
128.158.21.187 0:0:0:0:0:ffff:809e:15bb
128.158.21.188 0:0:0:0:0:ffff:809e:15bc
128.158.21.189 0:0:0:0:0:ffff:809e:15bd
128.158.21.190 0:0:0:0:0:ffff:809e:15be
128.158.21.191 0:0:0:0:0:ffff:809e:15bf
128.158.21.192 0:0:0:0:0:ffff:809e:15c0
128.158.21.193 0:0:0:0:0:ffff:809e:15c1
128.158.21.194 0:0:0:0:0:ffff:809e:15c2
128.158.21.195 0:0:0:0:0:ffff:809e:15c3
128.158.21.196 0:0:0:0:0:ffff:809e:15c4
128.158.21.197 0:0:0:0:0:ffff:809e:15c5
128.158.21.198 0:0:0:0:0:ffff:809e:15c6
128.158.21.199 0:0:0:0:0:ffff:809e:15c7
128.158.21.200 0:0:0:0:0:ffff:809e:15c8
128.158.21.201 0:0:0:0:0:ffff:809e:15c9
128.158.21.202 0:0:0:0:0:ffff:809e:15ca
128.158.21.203 0:0:0:0:0:ffff:809e:15cb
128.158.21.204 0:0:0:0:0:ffff:809e:15cc
128.158.21.205 0:0:0:0:0:ffff:809e:15cd
128.158.21.206 0:0:0:0:0:ffff:809e:15ce
128.158.21.207 0:0:0:0:0:ffff:809e:15cf
128.158.21.208 0:0:0:0:0:ffff:809e:15d0
128.158.21.209 0:0:0:0:0:ffff:809e:15d1
128.158.21.210 0:0:0:0:0:ffff:809e:15d2
128.158.21.211 0:0:0:0:0:ffff:809e:15d3
128.158.21.212 0:0:0:0:0:ffff:809e:15d4
128.158.21.213 0:0:0:0:0:ffff:809e:15d5
128.158.21.214 0:0:0:0:0:ffff:809e:15d6
128.158.21.215 0:0:0:0:0:ffff:809e:15d7
128.158.21.216 0:0:0:0:0:ffff:809e:15d8
128.158.21.217 0:0:0:0:0:ffff:809e:15d9
128.158.21.218 0:0:0:0:0:ffff:809e:15da
128.158.21.219 0:0:0:0:0:ffff:809e:15db
128.158.21.220 0:0:0:0:0:ffff:809e:15dc
128.158.21.221 0:0:0:0:0:ffff:809e:15dd
128.158.21.222 0:0:0:0:0:ffff:809e:15de
128.158.21.223 0:0:0:0:0:ffff:809e:15df
128.158.21.224 0:0:0:0:0:ffff:809e:15e0
128.158.21.225 0:0:0:0:0:ffff:809e:15e1
128.158.21.226 0:0:0:0:0:ffff:809e:15e2
128.158.21.227 0:0:0:0:0:ffff:809e:15e3
128.158.21.228 0:0:0:0:0:ffff:809e:15e4
128.158.21.229 0:0:0:0:0:ffff:809e:15e5
128.158.21.230 0:0:0:0:0:ffff:809e:15e6
128.158.21.231 0:0:0:0:0:ffff:809e:15e7
128.158.21.232 0:0:0:0:0:ffff:809e:15e8
128.158.21.233 0:0:0:0:0:ffff:809e:15e9
128.158.21.234 0:0:0:0:0:ffff:809e:15ea
128.158.21.235 0:0:0:0:0:ffff:809e:15eb
128.158.21.236 0:0:0:0:0:ffff:809e:15ec
128.158.21.237 0:0:0:0:0:ffff:809e:15ed
128.158.21.238 0:0:0:0:0:ffff:809e:15ee
128.158.21.239 0:0:0:0:0:ffff:809e:15ef
128.158.21.240 0:0:0:0:0:ffff:809e:15f0
128.158.21.241 0:0:0:0:0:ffff:809e:15f1
128.158.21.242 0:0:0:0:0:ffff:809e:15f2
128.158.21.243 0:0:0:0:0:ffff:809e:15f3
128.158.21.244 0:0:0:0:0:ffff:809e:15f4
128.158.21.245 0:0:0:0:0:ffff:809e:15f5
128.158.21.246 0:0:0:0:0:ffff:809e:15f6
128.158.21.247 0:0:0:0:0:ffff:809e:15f7
128.158.21.248 0:0:0:0:0:ffff:809e:15f8
128.158.21.249 0:0:0:0:0:ffff:809e:15f9
128.158.21.250 0:0:0:0:0:ffff:809e:15fa
128.158.21.251 0:0:0:0:0:ffff:809e:15fb
128.158.21.252 0:0:0:0:0:ffff:809e:15fc
128.158.21.253 0:0:0:0:0:ffff:809e:15fd
128.158.21.254 0:0:0:0:0:ffff:809e:15fe
128.158.21.255 0:0:0:0:0:ffff:809e:15ff


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.