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Networking - Subnet Masks
| | Addresses | Hosts | Netmask | Amount of a Class C |
| /30 | 4 | 2 | 255.255.255.252 | 1/64 |
| /29 | 8 | 6 | 255.255.255.248 | 1/32 |
| /28 | 16 | 14 | 255.255.255.240 | 1/16 |
| /27 | 32 | 30 | 255.255.255.224 | 1/8 |
| /26 | 64 | 62 | 255.255.255.192 | 1/4 |
| /25 | 128 | 126 | 255.255.255.128 | 1/2 |
| /24 | 256 | 254 | 255.255.255.0 | 1 |
| /23 | 512 | 510 | 255.255.254.0 | 2 |
| /22 | 1024 | 1022 | 255.255.252.0 | 4 |
| /21 | 2048 | 2046 | 255.255.248.0 | 8 |
| /20 | 4096 | 4094 | 255.255.240.0 | 16 |
| /19 | 8192 | 8190 | 255.255.224.0 | 32 |
| /18 | 16384 | 16382 | 255.255.192.0 | 64 |
| /17 | 32768 | 32766 | 255.255.128.0 | 128 |
| /16 | 65536 | 65534 | 255.255.0.0 | 256 |
Guide to sub-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 |
References
