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
21.251.205.1 0:0:0:0:0:ffff:15fb:cd01
21.251.205.2 0:0:0:0:0:ffff:15fb:cd02
21.251.205.3 0:0:0:0:0:ffff:15fb:cd03
21.251.205.4 0:0:0:0:0:ffff:15fb:cd04
21.251.205.5 0:0:0:0:0:ffff:15fb:cd05
21.251.205.6 0:0:0:0:0:ffff:15fb:cd06
21.251.205.7 0:0:0:0:0:ffff:15fb:cd07
21.251.205.8 0:0:0:0:0:ffff:15fb:cd08
21.251.205.9 0:0:0:0:0:ffff:15fb:cd09
21.251.205.10 0:0:0:0:0:ffff:15fb:cd0a
21.251.205.11 0:0:0:0:0:ffff:15fb:cd0b
21.251.205.12 0:0:0:0:0:ffff:15fb:cd0c
21.251.205.13 0:0:0:0:0:ffff:15fb:cd0d
21.251.205.14 0:0:0:0:0:ffff:15fb:cd0e
21.251.205.15 0:0:0:0:0:ffff:15fb:cd0f
21.251.205.16 0:0:0:0:0:ffff:15fb:cd10
21.251.205.17 0:0:0:0:0:ffff:15fb:cd11
21.251.205.18 0:0:0:0:0:ffff:15fb:cd12
21.251.205.19 0:0:0:0:0:ffff:15fb:cd13
21.251.205.20 0:0:0:0:0:ffff:15fb:cd14
21.251.205.21 0:0:0:0:0:ffff:15fb:cd15
21.251.205.22 0:0:0:0:0:ffff:15fb:cd16
21.251.205.23 0:0:0:0:0:ffff:15fb:cd17
21.251.205.24 0:0:0:0:0:ffff:15fb:cd18
21.251.205.25 0:0:0:0:0:ffff:15fb:cd19
21.251.205.26 0:0:0:0:0:ffff:15fb:cd1a
21.251.205.27 0:0:0:0:0:ffff:15fb:cd1b
21.251.205.28 0:0:0:0:0:ffff:15fb:cd1c
21.251.205.29 0:0:0:0:0:ffff:15fb:cd1d
21.251.205.30 0:0:0:0:0:ffff:15fb:cd1e
21.251.205.31 0:0:0:0:0:ffff:15fb:cd1f
21.251.205.32 0:0:0:0:0:ffff:15fb:cd20
21.251.205.33 0:0:0:0:0:ffff:15fb:cd21
21.251.205.34 0:0:0:0:0:ffff:15fb:cd22
21.251.205.35 0:0:0:0:0:ffff:15fb:cd23
21.251.205.36 0:0:0:0:0:ffff:15fb:cd24
21.251.205.37 0:0:0:0:0:ffff:15fb:cd25
21.251.205.38 0:0:0:0:0:ffff:15fb:cd26
21.251.205.39 0:0:0:0:0:ffff:15fb:cd27
21.251.205.40 0:0:0:0:0:ffff:15fb:cd28
21.251.205.41 0:0:0:0:0:ffff:15fb:cd29
21.251.205.42 0:0:0:0:0:ffff:15fb:cd2a
21.251.205.43 0:0:0:0:0:ffff:15fb:cd2b
21.251.205.44 0:0:0:0:0:ffff:15fb:cd2c
21.251.205.45 0:0:0:0:0:ffff:15fb:cd2d
21.251.205.46 0:0:0:0:0:ffff:15fb:cd2e
21.251.205.47 0:0:0:0:0:ffff:15fb:cd2f
21.251.205.48 0:0:0:0:0:ffff:15fb:cd30
21.251.205.49 0:0:0:0:0:ffff:15fb:cd31
21.251.205.50 0:0:0:0:0:ffff:15fb:cd32
21.251.205.51 0:0:0:0:0:ffff:15fb:cd33
21.251.205.52 0:0:0:0:0:ffff:15fb:cd34
21.251.205.53 0:0:0:0:0:ffff:15fb:cd35
21.251.205.54 0:0:0:0:0:ffff:15fb:cd36
21.251.205.55 0:0:0:0:0:ffff:15fb:cd37
21.251.205.56 0:0:0:0:0:ffff:15fb:cd38
21.251.205.57 0:0:0:0:0:ffff:15fb:cd39
21.251.205.58 0:0:0:0:0:ffff:15fb:cd3a
21.251.205.59 0:0:0:0:0:ffff:15fb:cd3b
21.251.205.60 0:0:0:0:0:ffff:15fb:cd3c


21.251.205.61 0:0:0:0:0:ffff:15fb:cd3d
21.251.205.62 0:0:0:0:0:ffff:15fb:cd3e
21.251.205.63 0:0:0:0:0:ffff:15fb:cd3f
21.251.205.64 0:0:0:0:0:ffff:15fb:cd40
21.251.205.65 0:0:0:0:0:ffff:15fb:cd41
21.251.205.66 0:0:0:0:0:ffff:15fb:cd42
21.251.205.67 0:0:0:0:0:ffff:15fb:cd43
21.251.205.68 0:0:0:0:0:ffff:15fb:cd44
21.251.205.69 0:0:0:0:0:ffff:15fb:cd45
21.251.205.70 0:0:0:0:0:ffff:15fb:cd46
21.251.205.71 0:0:0:0:0:ffff:15fb:cd47
21.251.205.72 0:0:0:0:0:ffff:15fb:cd48
21.251.205.73 0:0:0:0:0:ffff:15fb:cd49
21.251.205.74 0:0:0:0:0:ffff:15fb:cd4a
21.251.205.75 0:0:0:0:0:ffff:15fb:cd4b
21.251.205.76 0:0:0:0:0:ffff:15fb:cd4c
21.251.205.77 0:0:0:0:0:ffff:15fb:cd4d
21.251.205.78 0:0:0:0:0:ffff:15fb:cd4e
21.251.205.79 0:0:0:0:0:ffff:15fb:cd4f
21.251.205.80 0:0:0:0:0:ffff:15fb:cd50
21.251.205.81 0:0:0:0:0:ffff:15fb:cd51
21.251.205.82 0:0:0:0:0:ffff:15fb:cd52
21.251.205.83 0:0:0:0:0:ffff:15fb:cd53
21.251.205.84 0:0:0:0:0:ffff:15fb:cd54
21.251.205.85 0:0:0:0:0:ffff:15fb:cd55
21.251.205.86 0:0:0:0:0:ffff:15fb:cd56
21.251.205.87 0:0:0:0:0:ffff:15fb:cd57
21.251.205.88 0:0:0:0:0:ffff:15fb:cd58
21.251.205.89 0:0:0:0:0:ffff:15fb:cd59
21.251.205.90 0:0:0:0:0:ffff:15fb:cd5a
21.251.205.91 0:0:0:0:0:ffff:15fb:cd5b
21.251.205.92 0:0:0:0:0:ffff:15fb:cd5c
21.251.205.93 0:0:0:0:0:ffff:15fb:cd5d
21.251.205.94 0:0:0:0:0:ffff:15fb:cd5e
21.251.205.95 0:0:0:0:0:ffff:15fb:cd5f
21.251.205.96 0:0:0:0:0:ffff:15fb:cd60
21.251.205.97 0:0:0:0:0:ffff:15fb:cd61
21.251.205.98 0:0:0:0:0:ffff:15fb:cd62
21.251.205.99 0:0:0:0:0:ffff:15fb:cd63
21.251.205.100 0:0:0:0:0:ffff:15fb:cd64
21.251.205.101 0:0:0:0:0:ffff:15fb:cd65
21.251.205.102 0:0:0:0:0:ffff:15fb:cd66
21.251.205.103 0:0:0:0:0:ffff:15fb:cd67
21.251.205.104 0:0:0:0:0:ffff:15fb:cd68
21.251.205.105 0:0:0:0:0:ffff:15fb:cd69
21.251.205.106 0:0:0:0:0:ffff:15fb:cd6a
21.251.205.107 0:0:0:0:0:ffff:15fb:cd6b
21.251.205.108 0:0:0:0:0:ffff:15fb:cd6c
21.251.205.109 0:0:0:0:0:ffff:15fb:cd6d
21.251.205.110 0:0:0:0:0:ffff:15fb:cd6e
21.251.205.111 0:0:0:0:0:ffff:15fb:cd6f
21.251.205.112 0:0:0:0:0:ffff:15fb:cd70
21.251.205.113 0:0:0:0:0:ffff:15fb:cd71
21.251.205.114 0:0:0:0:0:ffff:15fb:cd72
21.251.205.115 0:0:0:0:0:ffff:15fb:cd73
21.251.205.116 0:0:0:0:0:ffff:15fb:cd74
21.251.205.117 0:0:0:0:0:ffff:15fb:cd75
21.251.205.118 0:0:0:0:0:ffff:15fb:cd76
21.251.205.119 0:0:0:0:0:ffff:15fb:cd77
21.251.205.120 0:0:0:0:0:ffff:15fb:cd78


21.251.205.121 0:0:0:0:0:ffff:15fb:cd79
21.251.205.122 0:0:0:0:0:ffff:15fb:cd7a
21.251.205.123 0:0:0:0:0:ffff:15fb:cd7b
21.251.205.124 0:0:0:0:0:ffff:15fb:cd7c
21.251.205.125 0:0:0:0:0:ffff:15fb:cd7d
21.251.205.126 0:0:0:0:0:ffff:15fb:cd7e
21.251.205.127 0:0:0:0:0:ffff:15fb:cd7f
21.251.205.128 0:0:0:0:0:ffff:15fb:cd80
21.251.205.129 0:0:0:0:0:ffff:15fb:cd81
21.251.205.130 0:0:0:0:0:ffff:15fb:cd82
21.251.205.131 0:0:0:0:0:ffff:15fb:cd83
21.251.205.132 0:0:0:0:0:ffff:15fb:cd84
21.251.205.133 0:0:0:0:0:ffff:15fb:cd85
21.251.205.134 0:0:0:0:0:ffff:15fb:cd86
21.251.205.135 0:0:0:0:0:ffff:15fb:cd87
21.251.205.136 0:0:0:0:0:ffff:15fb:cd88
21.251.205.137 0:0:0:0:0:ffff:15fb:cd89
21.251.205.138 0:0:0:0:0:ffff:15fb:cd8a
21.251.205.139 0:0:0:0:0:ffff:15fb:cd8b
21.251.205.140 0:0:0:0:0:ffff:15fb:cd8c
21.251.205.141 0:0:0:0:0:ffff:15fb:cd8d
21.251.205.142 0:0:0:0:0:ffff:15fb:cd8e
21.251.205.143 0:0:0:0:0:ffff:15fb:cd8f
21.251.205.144 0:0:0:0:0:ffff:15fb:cd90
21.251.205.145 0:0:0:0:0:ffff:15fb:cd91
21.251.205.146 0:0:0:0:0:ffff:15fb:cd92
21.251.205.147 0:0:0:0:0:ffff:15fb:cd93
21.251.205.148 0:0:0:0:0:ffff:15fb:cd94
21.251.205.149 0:0:0:0:0:ffff:15fb:cd95
21.251.205.150 0:0:0:0:0:ffff:15fb:cd96
21.251.205.151 0:0:0:0:0:ffff:15fb:cd97
21.251.205.152 0:0:0:0:0:ffff:15fb:cd98
21.251.205.153 0:0:0:0:0:ffff:15fb:cd99
21.251.205.154 0:0:0:0:0:ffff:15fb:cd9a
21.251.205.155 0:0:0:0:0:ffff:15fb:cd9b
21.251.205.156 0:0:0:0:0:ffff:15fb:cd9c
21.251.205.157 0:0:0:0:0:ffff:15fb:cd9d
21.251.205.158 0:0:0:0:0:ffff:15fb:cd9e
21.251.205.159 0:0:0:0:0:ffff:15fb:cd9f
21.251.205.160 0:0:0:0:0:ffff:15fb:cda0
21.251.205.161 0:0:0:0:0:ffff:15fb:cda1
21.251.205.162 0:0:0:0:0:ffff:15fb:cda2
21.251.205.163 0:0:0:0:0:ffff:15fb:cda3
21.251.205.164 0:0:0:0:0:ffff:15fb:cda4
21.251.205.165 0:0:0:0:0:ffff:15fb:cda5
21.251.205.166 0:0:0:0:0:ffff:15fb:cda6
21.251.205.167 0:0:0:0:0:ffff:15fb:cda7
21.251.205.168 0:0:0:0:0:ffff:15fb:cda8
21.251.205.169 0:0:0:0:0:ffff:15fb:cda9
21.251.205.170 0:0:0:0:0:ffff:15fb:cdaa
21.251.205.171 0:0:0:0:0:ffff:15fb:cdab
21.251.205.172 0:0:0:0:0:ffff:15fb:cdac
21.251.205.173 0:0:0:0:0:ffff:15fb:cdad
21.251.205.174 0:0:0:0:0:ffff:15fb:cdae
21.251.205.175 0:0:0:0:0:ffff:15fb:cdaf
21.251.205.176 0:0:0:0:0:ffff:15fb:cdb0
21.251.205.177 0:0:0:0:0:ffff:15fb:cdb1
21.251.205.178 0:0:0:0:0:ffff:15fb:cdb2
21.251.205.179 0:0:0:0:0:ffff:15fb:cdb3
21.251.205.180 0:0:0:0:0:ffff:15fb:cdb4


21.251.205.181 0:0:0:0:0:ffff:15fb:cdb5
21.251.205.182 0:0:0:0:0:ffff:15fb:cdb6
21.251.205.183 0:0:0:0:0:ffff:15fb:cdb7
21.251.205.184 0:0:0:0:0:ffff:15fb:cdb8
21.251.205.185 0:0:0:0:0:ffff:15fb:cdb9
21.251.205.186 0:0:0:0:0:ffff:15fb:cdba
21.251.205.187 0:0:0:0:0:ffff:15fb:cdbb
21.251.205.188 0:0:0:0:0:ffff:15fb:cdbc
21.251.205.189 0:0:0:0:0:ffff:15fb:cdbd
21.251.205.190 0:0:0:0:0:ffff:15fb:cdbe
21.251.205.191 0:0:0:0:0:ffff:15fb:cdbf
21.251.205.192 0:0:0:0:0:ffff:15fb:cdc0
21.251.205.193 0:0:0:0:0:ffff:15fb:cdc1
21.251.205.194 0:0:0:0:0:ffff:15fb:cdc2
21.251.205.195 0:0:0:0:0:ffff:15fb:cdc3
21.251.205.196 0:0:0:0:0:ffff:15fb:cdc4
21.251.205.197 0:0:0:0:0:ffff:15fb:cdc5
21.251.205.198 0:0:0:0:0:ffff:15fb:cdc6
21.251.205.199 0:0:0:0:0:ffff:15fb:cdc7
21.251.205.200 0:0:0:0:0:ffff:15fb:cdc8
21.251.205.201 0:0:0:0:0:ffff:15fb:cdc9
21.251.205.202 0:0:0:0:0:ffff:15fb:cdca
21.251.205.203 0:0:0:0:0:ffff:15fb:cdcb
21.251.205.204 0:0:0:0:0:ffff:15fb:cdcc
21.251.205.205 0:0:0:0:0:ffff:15fb:cdcd
21.251.205.206 0:0:0:0:0:ffff:15fb:cdce
21.251.205.207 0:0:0:0:0:ffff:15fb:cdcf
21.251.205.208 0:0:0:0:0:ffff:15fb:cdd0
21.251.205.209 0:0:0:0:0:ffff:15fb:cdd1
21.251.205.210 0:0:0:0:0:ffff:15fb:cdd2
21.251.205.211 0:0:0:0:0:ffff:15fb:cdd3
21.251.205.212 0:0:0:0:0:ffff:15fb:cdd4
21.251.205.213 0:0:0:0:0:ffff:15fb:cdd5
21.251.205.214 0:0:0:0:0:ffff:15fb:cdd6
21.251.205.215 0:0:0:0:0:ffff:15fb:cdd7
21.251.205.216 0:0:0:0:0:ffff:15fb:cdd8
21.251.205.217 0:0:0:0:0:ffff:15fb:cdd9
21.251.205.218 0:0:0:0:0:ffff:15fb:cdda
21.251.205.219 0:0:0:0:0:ffff:15fb:cddb
21.251.205.220 0:0:0:0:0:ffff:15fb:cddc
21.251.205.221 0:0:0:0:0:ffff:15fb:cddd
21.251.205.222 0:0:0:0:0:ffff:15fb:cdde
21.251.205.223 0:0:0:0:0:ffff:15fb:cddf
21.251.205.224 0:0:0:0:0:ffff:15fb:cde0
21.251.205.225 0:0:0:0:0:ffff:15fb:cde1
21.251.205.226 0:0:0:0:0:ffff:15fb:cde2
21.251.205.227 0:0:0:0:0:ffff:15fb:cde3
21.251.205.228 0:0:0:0:0:ffff:15fb:cde4
21.251.205.229 0:0:0:0:0:ffff:15fb:cde5
21.251.205.230 0:0:0:0:0:ffff:15fb:cde6
21.251.205.231 0:0:0:0:0:ffff:15fb:cde7
21.251.205.232 0:0:0:0:0:ffff:15fb:cde8
21.251.205.233 0:0:0:0:0:ffff:15fb:cde9
21.251.205.234 0:0:0:0:0:ffff:15fb:cdea
21.251.205.235 0:0:0:0:0:ffff:15fb:cdeb
21.251.205.236 0:0:0:0:0:ffff:15fb:cdec
21.251.205.237 0:0:0:0:0:ffff:15fb:cded
21.251.205.238 0:0:0:0:0:ffff:15fb:cdee
21.251.205.239 0:0:0:0:0:ffff:15fb:cdef
21.251.205.240 0:0:0:0:0:ffff:15fb:cdf0
21.251.205.241 0:0:0:0:0:ffff:15fb:cdf1
21.251.205.242 0:0:0:0:0:ffff:15fb:cdf2
21.251.205.243 0:0:0:0:0:ffff:15fb:cdf3
21.251.205.244 0:0:0:0:0:ffff:15fb:cdf4
21.251.205.245 0:0:0:0:0:ffff:15fb:cdf5
21.251.205.246 0:0:0:0:0:ffff:15fb:cdf6
21.251.205.247 0:0:0:0:0:ffff:15fb:cdf7
21.251.205.248 0:0:0:0:0:ffff:15fb:cdf8
21.251.205.249 0:0:0:0:0:ffff:15fb:cdf9
21.251.205.250 0:0:0:0:0:ffff:15fb:cdfa
21.251.205.251 0:0:0:0:0:ffff:15fb:cdfb
21.251.205.252 0:0:0:0:0:ffff:15fb:cdfc
21.251.205.253 0:0:0:0:0:ffff:15fb:cdfd
21.251.205.254 0:0:0:0:0:ffff:15fb:cdfe
21.251.205.255 0:0:0:0:0:ffff:15fb:cdff


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.