| Network/Host | Valid Addresses for | Network | Host IDs/ | Default | |||||||||
| Addresses | Network & Hosts | Class | Use | Ranges | IDs | Network | Subnet Mask | ||||||
| N . H . H . H | 1-126.0.0.0 | A | Large networks | 1-126/8 | 126 | 16,777,214 | 255.0.0.0 | ||||||
| X.256*256*256=16,777,216 (-2) = 16,777,214 Number of Host IDs from last three octets. | |||||||||||||
| N . N . H . H | 128-191.0-255.0.0 | B | Mid-sized Networks | 128-191/16 | 16,384 | 65,534 | 255.255.0.0 | ||||||
| 64*256 = 16,384 Total number of Class B IDs. | |||||||||||||
| N . N . N . H | 192-223.192-223.192-223.0 | C | Small Network | 192-223/24 | 2,097,152 | 254 | 255.255.255.0 | ||||||
| 32*256*256 = 2,097,152 possible Class C Network IDs. | |||||||||||||
| N . N . N . N/H | 224-239.224.239.224.239.224.239 | D | Multicast | 224-239 | |||||||||
| 224.0.0.0-239.255.255.255 | |||||||||||||
| E | Experimental | 240-247 | |||||||||||
| 240.0.0.0+ | |||||||||||||
| Extras | 247-254 | ||||||||||||
| NOTE: Cannot use 127.0.0.1 is the NIC loopback | |||||||||||||
| NOTE: Cannot use "1"'s or all zeros. | |||||||||||||
| Default Subnet Masks (SNM) | |||||||||||||
| BINARY CHART: | Class A | ||||||||||||
| 11111111.00000000.00000000.00000000 | |||||||||||||
| 128 64 32 16 8 4 2 1 | 255.0.0.0 | ||||||||||||
| 2^7 2^6 2^5 2^4 2^3 2^2 2^1 2^0 | |||||||||||||
| Class B | |||||||||||||
| 128 192 224 240 248 252 254 255 | 11111111.11111111.00000000.00000000 | ||||||||||||
| 255.255.0.0 | |||||||||||||
| Class C | |||||||||||||
| 11111111.11111111.11111111.00000000 | |||||||||||||
| 255.255.255.0 | |||||||||||||