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
65.121.21.1 0:0:0:0:0:ffff:4179:1501
65.121.21.2 0:0:0:0:0:ffff:4179:1502
65.121.21.3 0:0:0:0:0:ffff:4179:1503
65.121.21.4 0:0:0:0:0:ffff:4179:1504
65.121.21.5 0:0:0:0:0:ffff:4179:1505
65.121.21.6 0:0:0:0:0:ffff:4179:1506
65.121.21.7 0:0:0:0:0:ffff:4179:1507
65.121.21.8 0:0:0:0:0:ffff:4179:1508
65.121.21.9 0:0:0:0:0:ffff:4179:1509
65.121.21.10 0:0:0:0:0:ffff:4179:150a
65.121.21.11 0:0:0:0:0:ffff:4179:150b
65.121.21.12 0:0:0:0:0:ffff:4179:150c
65.121.21.13 0:0:0:0:0:ffff:4179:150d
65.121.21.14 0:0:0:0:0:ffff:4179:150e
65.121.21.15 0:0:0:0:0:ffff:4179:150f
65.121.21.16 0:0:0:0:0:ffff:4179:1510
65.121.21.17 0:0:0:0:0:ffff:4179:1511
65.121.21.18 0:0:0:0:0:ffff:4179:1512
65.121.21.19 0:0:0:0:0:ffff:4179:1513
65.121.21.20 0:0:0:0:0:ffff:4179:1514
65.121.21.21 0:0:0:0:0:ffff:4179:1515
65.121.21.22 0:0:0:0:0:ffff:4179:1516
65.121.21.23 0:0:0:0:0:ffff:4179:1517
65.121.21.24 0:0:0:0:0:ffff:4179:1518
65.121.21.25 0:0:0:0:0:ffff:4179:1519
65.121.21.26 0:0:0:0:0:ffff:4179:151a
65.121.21.27 0:0:0:0:0:ffff:4179:151b
65.121.21.28 0:0:0:0:0:ffff:4179:151c
65.121.21.29 0:0:0:0:0:ffff:4179:151d
65.121.21.30 0:0:0:0:0:ffff:4179:151e
65.121.21.31 0:0:0:0:0:ffff:4179:151f
65.121.21.32 0:0:0:0:0:ffff:4179:1520
65.121.21.33 0:0:0:0:0:ffff:4179:1521
65.121.21.34 0:0:0:0:0:ffff:4179:1522
65.121.21.35 0:0:0:0:0:ffff:4179:1523
65.121.21.36 0:0:0:0:0:ffff:4179:1524
65.121.21.37 0:0:0:0:0:ffff:4179:1525
65.121.21.38 0:0:0:0:0:ffff:4179:1526
65.121.21.39 0:0:0:0:0:ffff:4179:1527
65.121.21.40 0:0:0:0:0:ffff:4179:1528
65.121.21.41 0:0:0:0:0:ffff:4179:1529
65.121.21.42 0:0:0:0:0:ffff:4179:152a
65.121.21.43 0:0:0:0:0:ffff:4179:152b
65.121.21.44 0:0:0:0:0:ffff:4179:152c
65.121.21.45 0:0:0:0:0:ffff:4179:152d
65.121.21.46 0:0:0:0:0:ffff:4179:152e
65.121.21.47 0:0:0:0:0:ffff:4179:152f
65.121.21.48 0:0:0:0:0:ffff:4179:1530
65.121.21.49 0:0:0:0:0:ffff:4179:1531
65.121.21.50 0:0:0:0:0:ffff:4179:1532
65.121.21.51 0:0:0:0:0:ffff:4179:1533
65.121.21.52 0:0:0:0:0:ffff:4179:1534
65.121.21.53 0:0:0:0:0:ffff:4179:1535
65.121.21.54 0:0:0:0:0:ffff:4179:1536
65.121.21.55 0:0:0:0:0:ffff:4179:1537
65.121.21.56 0:0:0:0:0:ffff:4179:1538
65.121.21.57 0:0:0:0:0:ffff:4179:1539
65.121.21.58 0:0:0:0:0:ffff:4179:153a
65.121.21.59 0:0:0:0:0:ffff:4179:153b
65.121.21.60 0:0:0:0:0:ffff:4179:153c


65.121.21.61 0:0:0:0:0:ffff:4179:153d
65.121.21.62 0:0:0:0:0:ffff:4179:153e
65.121.21.63 0:0:0:0:0:ffff:4179:153f
65.121.21.64 0:0:0:0:0:ffff:4179:1540
65.121.21.65 0:0:0:0:0:ffff:4179:1541
65.121.21.66 0:0:0:0:0:ffff:4179:1542
65.121.21.67 0:0:0:0:0:ffff:4179:1543
65.121.21.68 0:0:0:0:0:ffff:4179:1544
65.121.21.69 0:0:0:0:0:ffff:4179:1545
65.121.21.70 0:0:0:0:0:ffff:4179:1546
65.121.21.71 0:0:0:0:0:ffff:4179:1547
65.121.21.72 0:0:0:0:0:ffff:4179:1548
65.121.21.73 0:0:0:0:0:ffff:4179:1549
65.121.21.74 0:0:0:0:0:ffff:4179:154a
65.121.21.75 0:0:0:0:0:ffff:4179:154b
65.121.21.76 0:0:0:0:0:ffff:4179:154c
65.121.21.77 0:0:0:0:0:ffff:4179:154d
65.121.21.78 0:0:0:0:0:ffff:4179:154e
65.121.21.79 0:0:0:0:0:ffff:4179:154f
65.121.21.80 0:0:0:0:0:ffff:4179:1550
65.121.21.81 0:0:0:0:0:ffff:4179:1551
65.121.21.82 0:0:0:0:0:ffff:4179:1552
65.121.21.83 0:0:0:0:0:ffff:4179:1553
65.121.21.84 0:0:0:0:0:ffff:4179:1554
65.121.21.85 0:0:0:0:0:ffff:4179:1555
65.121.21.86 0:0:0:0:0:ffff:4179:1556
65.121.21.87 0:0:0:0:0:ffff:4179:1557
65.121.21.88 0:0:0:0:0:ffff:4179:1558
65.121.21.89 0:0:0:0:0:ffff:4179:1559
65.121.21.90 0:0:0:0:0:ffff:4179:155a
65.121.21.91 0:0:0:0:0:ffff:4179:155b
65.121.21.92 0:0:0:0:0:ffff:4179:155c
65.121.21.93 0:0:0:0:0:ffff:4179:155d
65.121.21.94 0:0:0:0:0:ffff:4179:155e
65.121.21.95 0:0:0:0:0:ffff:4179:155f
65.121.21.96 0:0:0:0:0:ffff:4179:1560
65.121.21.97 0:0:0:0:0:ffff:4179:1561
65.121.21.98 0:0:0:0:0:ffff:4179:1562
65.121.21.99 0:0:0:0:0:ffff:4179:1563
65.121.21.100 0:0:0:0:0:ffff:4179:1564
65.121.21.101 0:0:0:0:0:ffff:4179:1565
65.121.21.102 0:0:0:0:0:ffff:4179:1566
65.121.21.103 0:0:0:0:0:ffff:4179:1567
65.121.21.104 0:0:0:0:0:ffff:4179:1568
65.121.21.105 0:0:0:0:0:ffff:4179:1569
65.121.21.106 0:0:0:0:0:ffff:4179:156a
65.121.21.107 0:0:0:0:0:ffff:4179:156b
65.121.21.108 0:0:0:0:0:ffff:4179:156c
65.121.21.109 0:0:0:0:0:ffff:4179:156d
65.121.21.110 0:0:0:0:0:ffff:4179:156e
65.121.21.111 0:0:0:0:0:ffff:4179:156f
65.121.21.112 0:0:0:0:0:ffff:4179:1570
65.121.21.113 0:0:0:0:0:ffff:4179:1571
65.121.21.114 0:0:0:0:0:ffff:4179:1572
65.121.21.115 0:0:0:0:0:ffff:4179:1573
65.121.21.116 0:0:0:0:0:ffff:4179:1574
65.121.21.117 0:0:0:0:0:ffff:4179:1575
65.121.21.118 0:0:0:0:0:ffff:4179:1576
65.121.21.119 0:0:0:0:0:ffff:4179:1577
65.121.21.120 0:0:0:0:0:ffff:4179:1578


65.121.21.121 0:0:0:0:0:ffff:4179:1579
65.121.21.122 0:0:0:0:0:ffff:4179:157a
65.121.21.123 0:0:0:0:0:ffff:4179:157b
65.121.21.124 0:0:0:0:0:ffff:4179:157c
65.121.21.125 0:0:0:0:0:ffff:4179:157d
65.121.21.126 0:0:0:0:0:ffff:4179:157e
65.121.21.127 0:0:0:0:0:ffff:4179:157f
65.121.21.128 0:0:0:0:0:ffff:4179:1580
65.121.21.129 0:0:0:0:0:ffff:4179:1581
65.121.21.130 0:0:0:0:0:ffff:4179:1582
65.121.21.131 0:0:0:0:0:ffff:4179:1583
65.121.21.132 0:0:0:0:0:ffff:4179:1584
65.121.21.133 0:0:0:0:0:ffff:4179:1585
65.121.21.134 0:0:0:0:0:ffff:4179:1586
65.121.21.135 0:0:0:0:0:ffff:4179:1587
65.121.21.136 0:0:0:0:0:ffff:4179:1588
65.121.21.137 0:0:0:0:0:ffff:4179:1589
65.121.21.138 0:0:0:0:0:ffff:4179:158a
65.121.21.139 0:0:0:0:0:ffff:4179:158b
65.121.21.140 0:0:0:0:0:ffff:4179:158c
65.121.21.141 0:0:0:0:0:ffff:4179:158d
65.121.21.142 0:0:0:0:0:ffff:4179:158e
65.121.21.143 0:0:0:0:0:ffff:4179:158f
65.121.21.144 0:0:0:0:0:ffff:4179:1590
65.121.21.145 0:0:0:0:0:ffff:4179:1591
65.121.21.146 0:0:0:0:0:ffff:4179:1592
65.121.21.147 0:0:0:0:0:ffff:4179:1593
65.121.21.148 0:0:0:0:0:ffff:4179:1594
65.121.21.149 0:0:0:0:0:ffff:4179:1595
65.121.21.150 0:0:0:0:0:ffff:4179:1596
65.121.21.151 0:0:0:0:0:ffff:4179:1597
65.121.21.152 0:0:0:0:0:ffff:4179:1598
65.121.21.153 0:0:0:0:0:ffff:4179:1599
65.121.21.154 0:0:0:0:0:ffff:4179:159a
65.121.21.155 0:0:0:0:0:ffff:4179:159b
65.121.21.156 0:0:0:0:0:ffff:4179:159c
65.121.21.157 0:0:0:0:0:ffff:4179:159d
65.121.21.158 0:0:0:0:0:ffff:4179:159e
65.121.21.159 0:0:0:0:0:ffff:4179:159f
65.121.21.160 0:0:0:0:0:ffff:4179:15a0
65.121.21.161 0:0:0:0:0:ffff:4179:15a1
65.121.21.162 0:0:0:0:0:ffff:4179:15a2
65.121.21.163 0:0:0:0:0:ffff:4179:15a3
65.121.21.164 0:0:0:0:0:ffff:4179:15a4
65.121.21.165 0:0:0:0:0:ffff:4179:15a5
65.121.21.166 0:0:0:0:0:ffff:4179:15a6
65.121.21.167 0:0:0:0:0:ffff:4179:15a7
65.121.21.168 0:0:0:0:0:ffff:4179:15a8
65.121.21.169 0:0:0:0:0:ffff:4179:15a9
65.121.21.170 0:0:0:0:0:ffff:4179:15aa
65.121.21.171 0:0:0:0:0:ffff:4179:15ab
65.121.21.172 0:0:0:0:0:ffff:4179:15ac
65.121.21.173 0:0:0:0:0:ffff:4179:15ad
65.121.21.174 0:0:0:0:0:ffff:4179:15ae
65.121.21.175 0:0:0:0:0:ffff:4179:15af
65.121.21.176 0:0:0:0:0:ffff:4179:15b0
65.121.21.177 0:0:0:0:0:ffff:4179:15b1
65.121.21.178 0:0:0:0:0:ffff:4179:15b2
65.121.21.179 0:0:0:0:0:ffff:4179:15b3
65.121.21.180 0:0:0:0:0:ffff:4179:15b4


65.121.21.181 0:0:0:0:0:ffff:4179:15b5
65.121.21.182 0:0:0:0:0:ffff:4179:15b6
65.121.21.183 0:0:0:0:0:ffff:4179:15b7
65.121.21.184 0:0:0:0:0:ffff:4179:15b8
65.121.21.185 0:0:0:0:0:ffff:4179:15b9
65.121.21.186 0:0:0:0:0:ffff:4179:15ba
65.121.21.187 0:0:0:0:0:ffff:4179:15bb
65.121.21.188 0:0:0:0:0:ffff:4179:15bc
65.121.21.189 0:0:0:0:0:ffff:4179:15bd
65.121.21.190 0:0:0:0:0:ffff:4179:15be
65.121.21.191 0:0:0:0:0:ffff:4179:15bf
65.121.21.192 0:0:0:0:0:ffff:4179:15c0
65.121.21.193 0:0:0:0:0:ffff:4179:15c1
65.121.21.194 0:0:0:0:0:ffff:4179:15c2
65.121.21.195 0:0:0:0:0:ffff:4179:15c3
65.121.21.196 0:0:0:0:0:ffff:4179:15c4
65.121.21.197 0:0:0:0:0:ffff:4179:15c5
65.121.21.198 0:0:0:0:0:ffff:4179:15c6
65.121.21.199 0:0:0:0:0:ffff:4179:15c7
65.121.21.200 0:0:0:0:0:ffff:4179:15c8
65.121.21.201 0:0:0:0:0:ffff:4179:15c9
65.121.21.202 0:0:0:0:0:ffff:4179:15ca
65.121.21.203 0:0:0:0:0:ffff:4179:15cb
65.121.21.204 0:0:0:0:0:ffff:4179:15cc
65.121.21.205 0:0:0:0:0:ffff:4179:15cd
65.121.21.206 0:0:0:0:0:ffff:4179:15ce
65.121.21.207 0:0:0:0:0:ffff:4179:15cf
65.121.21.208 0:0:0:0:0:ffff:4179:15d0
65.121.21.209 0:0:0:0:0:ffff:4179:15d1
65.121.21.210 0:0:0:0:0:ffff:4179:15d2
65.121.21.211 0:0:0:0:0:ffff:4179:15d3
65.121.21.212 0:0:0:0:0:ffff:4179:15d4
65.121.21.213 0:0:0:0:0:ffff:4179:15d5
65.121.21.214 0:0:0:0:0:ffff:4179:15d6
65.121.21.215 0:0:0:0:0:ffff:4179:15d7
65.121.21.216 0:0:0:0:0:ffff:4179:15d8
65.121.21.217 0:0:0:0:0:ffff:4179:15d9
65.121.21.218 0:0:0:0:0:ffff:4179:15da
65.121.21.219 0:0:0:0:0:ffff:4179:15db
65.121.21.220 0:0:0:0:0:ffff:4179:15dc
65.121.21.221 0:0:0:0:0:ffff:4179:15dd
65.121.21.222 0:0:0:0:0:ffff:4179:15de
65.121.21.223 0:0:0:0:0:ffff:4179:15df
65.121.21.224 0:0:0:0:0:ffff:4179:15e0
65.121.21.225 0:0:0:0:0:ffff:4179:15e1
65.121.21.226 0:0:0:0:0:ffff:4179:15e2
65.121.21.227 0:0:0:0:0:ffff:4179:15e3
65.121.21.228 0:0:0:0:0:ffff:4179:15e4
65.121.21.229 0:0:0:0:0:ffff:4179:15e5
65.121.21.230 0:0:0:0:0:ffff:4179:15e6
65.121.21.231 0:0:0:0:0:ffff:4179:15e7
65.121.21.232 0:0:0:0:0:ffff:4179:15e8
65.121.21.233 0:0:0:0:0:ffff:4179:15e9
65.121.21.234 0:0:0:0:0:ffff:4179:15ea
65.121.21.235 0:0:0:0:0:ffff:4179:15eb
65.121.21.236 0:0:0:0:0:ffff:4179:15ec
65.121.21.237 0:0:0:0:0:ffff:4179:15ed
65.121.21.238 0:0:0:0:0:ffff:4179:15ee
65.121.21.239 0:0:0:0:0:ffff:4179:15ef
65.121.21.240 0:0:0:0:0:ffff:4179:15f0
65.121.21.241 0:0:0:0:0:ffff:4179:15f1
65.121.21.242 0:0:0:0:0:ffff:4179:15f2
65.121.21.243 0:0:0:0:0:ffff:4179:15f3
65.121.21.244 0:0:0:0:0:ffff:4179:15f4
65.121.21.245 0:0:0:0:0:ffff:4179:15f5
65.121.21.246 0:0:0:0:0:ffff:4179:15f6
65.121.21.247 0:0:0:0:0:ffff:4179:15f7
65.121.21.248 0:0:0:0:0:ffff:4179:15f8
65.121.21.249 0:0:0:0:0:ffff:4179:15f9
65.121.21.250 0:0:0:0:0:ffff:4179:15fa
65.121.21.251 0:0:0:0:0:ffff:4179:15fb
65.121.21.252 0:0:0:0:0:ffff:4179:15fc
65.121.21.253 0:0:0:0:0:ffff:4179:15fd
65.121.21.254 0:0:0:0:0:ffff:4179:15fe
65.121.21.255 0:0:0:0:0:ffff:4179:15ff


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.