Свойства сетей класса A, B и C.
| Class A | Class B | Class C | |
| Первый октет | 1-126 | 128-191 | 192–223 |
| Доступные сети | 1.0.0.0–126.0.0.0 | 128.0.0.0–191.255.0.0 | 192.0.0.0–223.255.255.0 |
| Всего сетей в классе | 27 – 2 = 126 | 214 = 16,384 | 221 = 2,097,152 |
| Хостов в сети | 224 – 2 | 216 – 2 | 28 – 2 |
| Битов в сети | 8 | 16 | 24 |
| Битов в хосте | 24 | 16 | 8 |
| Маска по умолчанию | 255.0.0.0 | 255.255.0.0 | 255.255.255.0 |
Диапазон приватных IP адресов
| RFC1918 name | IP address range | Number of addresses | Largest CIDR block (subnet mask) | Host ID size | Mask bits |
| 24-bit block | 10.0.0.0 – 10.255.255.255 | 16777216 | 10.0.0.0/8 (255.0.0.0) | 24 bits | 8 bits |
| 20-bit block | 172.16.0.0 – 172.31.255.255 | 1048576 | 172.16.0.0/12 (255.240.0.0) | 20 bits | 12 bits |
| 16-bit block | 192.168.0.0 – 192.168.255.255 | 65536 | 192.168.0.0/16 (255.255.0.0) | 16 bits | 16 bits |
Различные значения сетевых масок
| Binary Mask Octets | Decimal Equivalent | Number of Binary 1s |
| 00000000 | 0 | 0 |
| 1000000 | 128 | 1 |
| 11000000 | 192 | 2 |
| 11100000 | 224 | 3 |
| 11110000 | 240 | 4 |
| 11111000 | 248 | 5 |
| 11111100 | 252 | 6 |
| 11111110 | 254 | 7 |
| 11111111 | 255 | 8 |
Class A
| Network Bits | Subnet Mask | Number of Subnets | Number of Hosts |
| /8 | 255.0.0.0 | 0 | 16777214 |
| /9 | 255.128.0.0 | 2 (0) | 8388606 |
| /10 | 255.192.0.0 | 4 (2) | 4194302 |
| /11 | 255.224.0.0 | 8 (6) | 2097150 |
| /12 | 255.240.0.0 | 16 (14) | 1048574 |
| /13 | 255.248.0.0 | 32 (30) | 524286 |
| /14 | 255.252.0.0 | 64 (62) | 262142 |
| /15 | 255.254.0.0 | 128 (126) | 131070 |
| /16 | 255.255.0.0 | 256 (254) | 65534 |
| /17 | 255.255.128.0 | 512 (510) | 32766 |
| /18 | 255.255.192.0 | 1024 (1022) | 16382 |
| /19 | 255.255.224.0 | 2048 (2046) | 8190 |
| /20 | 255.255.240.0 | 4096 (4094) | 4094 |
| /21 | 255.255.248.0 | 8192 (8190) | 2046 |
| /22 | 255.255.252.0 | 16384 (16382) | 1022 |
| /23 | 255.255.254.0 | 32768 (32766) | 510 |
| /24 | 255.255.255.0 | 65536 (65534) | 254 |
| /25 | 255.255.255.128 | 131072 (131070) | 126 |
| /26 | 255.255.255.192 | 262144 (262142) | 62 |
| /27 | 255.255.255.224 | 524288 (524286) | 30 |
| /28 | 255.255.255.240 | 1048576 (1048574) | 14 |
| /29 | 255.255.255.248 | 2097152 (2097150) | 6 |
| /30 | 255.255.255.252 | 4194304 (4194302) | 2 |
Class B
| Network Bits | Subnet Mask | Number of Subnets | Number of Hosts |
| /16 | 255.255.0.0 | 0 | 65534 |
| /17 | 255.255.128.0 | 2 (0) | 32766 |
| /18 | 255.255.192.0 | 4 (2) | 16382 |
| /19 | 255.255.224.0 | 8 (6) | 8190 |
| /20 | 255.255.240.0 | 16 (14) | 4094 |
| /21 | 255.255.248.0 | 32 (30) | 2046 |
| /22 | 255.255.252.0 | 64 (62) | 1022 |
| /23 | 255.255.254.0 | 128 (126) | 510 |
| /24 | 255.255.255.0 | 256 (254) | 254 |
| /25 | 255.255.255.128 | 512 (510) | 126 |
| /26 | 255.255.255.192 | 1024 (1022) | 62 |
| /27 | 255.255.255.224 | 2048 (2046) | 30 |
| /28 | 255.255.255.240 | 4096 (4094) | 14 |
| /29 | 255.255.255.248 | 8192 (8190) | 6 |
| /30 | 255.255.255.252 | 16384 (16382) | 2 |
Class C
| Network Bits | Subnet Mask | Number of Subnets | Number of Hosts |
| /24 | 255.255.255.0 | 0 | 254 |
| /25 | 255.255.255.128 | 2 (0) | 126 |
| /26 | 255.255.255.192 | 4 (2) | 62 |
| /27 | 255.255.255.224 | 8 (6) | 30 |
| /28 | 255.255.255.240 | 16 (14) | 14 |
| /29 | 255.255.255.248 | 32 (30) | 6 |
| /30 | 255.255.255.252 | 64 (62) | 2 |
Class D
| CIDR Block | Supernet Mask | Number of Class C Addresses | Number of Hosts |
| /14 | 255.252.0.0 | 1024 | 262144 |
| /15 | 255.254.0.0 | 512 | 131072 |
| /16 | 255.255.0.0 | 256 | 65536 |
| /17 | 255.255.128.0 | 128 | 32768 |
| /18 | 255.255.192.0 | 64 | 16384 |
| /19 | 255.255.224.0 | 32 | 8192 |
| /20 | 255.255.240.0 | 16 | 4096 |
| /21 | 255.255.248.0 | 8 | 2048 |
| /22 | 255.255.252.0 | 4 | 1024 |
| /23 | 255.255.254.0 | 2 | 512 |