Subnetting
IPv4 Classes
Class | Leading Bits | Start | End | Subnet Mask |
---|---|---|---|---|
A (CIDR /8) | 0 | 0.0.0.0 | 127.255.255.255 | 255.0.0.0 |
B (CIDR /16) | 10 | 128.0.0.0 | 191.255.255.255 | 255.255.0.0 |
C (CIDR /24) | 110 | 192.0.0.0 | 223.255.255.255 | 255.255.255.0 |
D | 1110 | 224.0.0.0 | 239.255.255.255 | Multicasting |
E | 1111 | 240.0.0.0 | 255.255.255.255 | Reserved |
IANA-Reserved IPv4 Network Ranges
Start | End | No. of Addresses | |
---|---|---|---|
24-bit Block (/8 Prefix, 1 x A) | 10.0.0.0 | 10.255.255.255 | 16,777,216 |
20-bit Block (/12 Prefix, 16 x B) | 172.16.0.0 | 172.31.255.255 | 1,048,576 |
16-bit Block (/16 Prefix, 256 x C) | 192.168.0.0 | 192.168.255.255 | 65,536 |
Class C Host/Subnet Table
Class C Bits | Subnet Mask | Effective Subnets | Effective Hosts | Number of Subnet Mask Bits | Binary Suffix |
---|---|---|---|---|---|
0 | 255.255.255.0 | 1 | 256 | /24 | 00000000 |
1 | 255.255.255.128 | 2 | 126 | /25 | 10000000 |
2 | 255.255.255.192 | 4 | 62 | /26 | 11000000 |
3 | 255.255.255.224 | 8 | 30 | /27 | 11100000 |
4 | 255.255.255.240 | 16 | 14 | /28 | 11110000 |
5 | 255.255.255.248 | 32 | 6 | /29 | 11111000 |
6 | 255.255.255.252 | 64 | 2 | /30 | 11111100 |
Class C Blocks
/25 -- 2 Subnets -- 126 Hosts/Subnet
Network # | IP Range | Broadcast |
---|---|---|
.0 | .1-.126 | .127 |
.128 | .129-.254 | .255 |
/26 -- 4 Subnets -- 62 Hosts/Subnet
Network # | IP Range | Broadcast |
---|---|---|
.0 | .1-.62 | .63 |
.64 | .65-.126 | .127 |
.128 | .129-.190 | .191 |
.192 | .193-.254 | .255 |
/27 -- 8 Subnets -- 30 Hosts/Subnet
Network # | IP Range | Broadcast |
---|---|---|
.0 | .1-.30 | .31 |
.32 | .33-.62 | .63 |
.64 | .65-.94 | .95 |
.96 | .97-.126 | .127 |
.128 | .129-.158 | .159 |
.160 | .161-.190 | .191 |
.192 | .193-.222 | .223 |
.224 | .225-.254 | .255 |
/28 -- 16 Subnets -- 14 Hosts/Subnet
Network # | IP Range | Broadcast |
---|---|---|
.0 | .1-.14 | .15 |
.16 | .17-.30 | .31 |
.32 | .33-.46 | .47 |
.48 | .49-.62 | .63 |
.64 | .65-.78 | .79 |
.80 | .81-.94 | .95 |
.96 | .97-.110 | .111 |
.112 | .113-.126 | .127 |
.128 | .129-.142 | .143 |
.144 | .145-.158 | .159 |
.160 | .161-.174 | .175 |
.176 | .177-.190 | .191 |
.192 | .193-.206 | .207 |
.208 | .209-.222 | .223 |
.224 | .225-.238 | .239 |
.240 | .241-.254 | .255 |
/29 -- 32 Subnets -- 6 Hosts/Subnet
Network # | IP Range | Broadcast |
---|---|---|
.0 | 1-.6 | .7 |
.8 | 9-.14 | .15 |
.16 | 17-.22 | .23 |
.24 | 25-.30 | .31 |
.32 | 33-.38 | .39 |
.40 | 41-.46 | .47 |
.48 | 49-.54 | .55 |
.56 | 57-.62 | .63 |
.64 | 65-.70 | .71 |
.72 | 73-.78 | .79 |
.80 | 81-.86 | .87 |
.88 | 89-.94 | .95 |
.96 | 97-.102 | .103 |
.104 | 105-.110 | .111 |
.112 | 113-.118 | .119 |
.120 | 121-.126 | .127 |
.128 | 129-.134 | .135 |
.136 | 137-.142 | .143 |
.144 | .145-.150 | .151 |
.152 | .153-.158 | .159 |
.160 | .161-.166 | .167 |
.168 | .169-.174 | .175 |
.176 | .177-.182 | .183 |
.184 | .185-.190 | .191 |
.192 | .193-.198 | .199 |
.200 | .201-.206 | .207 |
.208 | .209-.214 | .215 |
.216 | .217-.222 | .223 |
.224 | .225-.230 | .231 |
.232 | .233-.238 | .239 |
.240 | .241-.246 | .247 |
.248 | .249-.254 | .255 |
/30 -- 64 Subnets -- 2 Hosts/Subnet
Network # | IP Range | Broadcast |
---|---|---|
.0 | .1-.2 | .3 |
.4 | .5-.6 | .7 |
.8 | .9-.10 | .11 |
.12 | .13-.14 | .15 |
.16 | .17-.18 | .19 |
.20 | .21-.22 | .23 |
.24 | .25-.26 | .27 |
.28 | .29-.30 | .31 |
.32 | .33-.34 | .35 |
.36 | .37-.38 | .39 |
.40 | .41-.42 | .43 |
.44 | .45-.46 | .47 |
.48 | .49-.50 | .51 |
.52 | .53-.54 | .55 |
.56 | .57-.58 | .59 |
.60 | .61-.62 | .63 |
.64 | .65-.66 | .67 |
.68 | .69-.70 | .71 |
.72 | .73-.74 | .75 |
.76 | .77-.78 | .79 |
.80 | .81-.82 | .83 |
.84 | .85-.86 | .87 |
.88 | .89-.90 | .91 |
.92 | .93-.94 | .95 |
.96 | .97-.98 | .99 |
.100 | .101-.102 | .103 |
.104 | .105-.106 | .107 |
.108 | .109-.110 | .111 |
.112 | .113-.114 | .115 |
.116 | .117-.118 | .119 |
.120 | .121-.122 | .123 |
.124 | .125-.126 | .127 |
.128 | .129-.130 | .131 |
.132 | .133-.134 | .135 |
.136 | .137-.138 | .139 |
.140 | .141-.142 | .143 |
.144 | .145-.146 | .147 |
.148 | .149-.150 | .151 |
.152 | .153-.154 | .155 |
.156 | .157-.158 | .159 |
.160 | .161-.162 | .163 |
.164 | .165-.166 | .167 |
.168 | .169-.170 | .171 |
.172 | .173-.174 | .175 |
.176 | .177-.178 | .179 |
.180 | .181-.182 | .183 |
.184 | .185-.186 | .187 |
.188 | .189-.190 | .191 |
.192 | .193-.194 | .195 |
.196 | .197-.198 | .199 |
.200 | .201-.202 | .203 |
.204 | .205-.206 | .207 |
.208 | .209-.210 | .211 |
.212 | .213-.214 | .215 |
.216 | .217-.218 | .219 |
.220 | .221-.222 | .223 |
.224 | .225-.226 | .227 |
.228 | .229-.230 | .231 |
.232 | .233-.234 | .235 |
.236 | .237-.238 | .239 |
.240 | .241-.242 | .243 |
.244 | .245-.246 | .247 |
.248 | .249-.250 | .251 |
.252 | .253-.254 | .255 |