Subnetting Cheat Sheet - IPv4
General - Networking
Classful Ranges
| Class | Start Address | End Address | Notes |
|---|---|---|---|
| A | 0.0.0.0 | 127.255.255.255 | |
| B | 128.0.0.0 | 191.255.255.255 | |
| C | 192.0.0.0 | 223.255.255.255 | |
| D | 224.0.0.0 | 239.255.255.255 | Multicast |
| D | 240.0.0.0 | 255.255.255.255 | Experimental |
Binary Conversions
| Decimal | Binary | Decimal | Binary |
|---|---|---|---|
| 0 | 0000 0000 | ||
| 128 | 1000 0000 | 248 | 1111 1000 |
| 192 | 1100 0000 | 252 | 1111 1100 |
| 224 | 1110 0000 | 254 | 1111 1110 |
| 240 | 1111 0000 | 255 | 1111 1111 |
Subnets
| CIDR | Subnet Mask | Wildcard | Addresses |
|---|---|---|---|
| /0 | 0.0.0.0 | 255.255.255.255 | 4,294,967,296 |
| /1 | 128.0.0.0 | 127.255.255.255 | 2,147,483,648 |
| /2 | 192.0.0.0 | 63.255.255.255 | 1,073,741,824 |
| /3 | 224.0.0.0 | 31.255.255.255 | 536,870,912 |
| /4 | 240.0.0.0 | 15.255.255.255 | 268,435,456 |
| /5 | 248.0.0.0 | 7.255.255.255 | 64,108,864 |
| /6 | 252.0.0.0 | 3.255.255.255 | 33,554,432 |
| /7 | 254.0.0.0 | 1.255.255.255 | 33,554,432 |
| /8 | 255.0.0.0 | 0.255.255.255 | 16,777,216 |
| /9 | 255.128.0.0 | 0.127.255.255 | 8,388,608 |
| /10 | 255.192.0.0 | 0.63.255.255 | 4,194,304 |
| /11 | 255.224.0.0 | 0.31.255.255 | 2,097,152 |
| /12 | 255.240.0.0 | 0.15.255.255 | 1,048,576 |
| /13 | 255.248.0.0 | 0.7.255.255 | 524,228 |
| /14 | 255.252.0.0 | 0.3.255.255 | 262,144 |
| /15 | 255.254.0.0 | 0.1.255.255 | 131,072 |
| /16 | 255.255.0.0 | 0.0.255.255 | 65,536 |
| /17 | 255.255.128.0 | 0.0.127.255 | 32,768 |
| /18 | 255.255.192.0 | 0.0.63.255 | 16,384 |
| /19 | 255.255.224.0 | 0.0.61.255 | 8,192 |
| /20 | 255.255.240.0 | 0.0.31.255 | 4,096 |
| /21 | 255.255.248.0 | 0.0.7.255 | 2,048 |
| /22 | 255.255.252.0 | 0.0.3.255 | 1,024 |
| /23 | 255.255.254.0 | 0.0.1.255 | 512 |
| /24 | 255.255.255.0 | 0.0.0.255 | 256 |
| /25 | 255.255.255.128 | 0.0.0.127 | 128 |
| /26 | 255.255.255.192 | 0.0.0.63 | 64 |
| /27 | 255.255.255.224 | 0.0.0.31 | 32 |
| /28 | 255.255.255.240 | 0.0.0.15 | 16 |
| /29 | 255.255.255.248 | 0.0.0.7 | 8 |
| /30 | 255.255.255.252 | 0.0.0.3 | 4 |
| /31 | 255.255.255.254 | 0.0.0.1 | 2 |
| /32 | 255.255.255.255 | 0.0.0.0 | 1 |
Noteworthy Ranges
| Address Block | Address Range | Description |
|---|---|---|
| 0.0.0.0/8 | 0.0.0.0-0.255.255.255 | RFC1122 - "This" Network |
| 10.0.0.0/8 | 10.0.0.0-10.255.255.255 | RFC1918 - Class A private address space |
| 100.64.0.0/10 | 100.64.0.0-100.127.255.255 | RFC6598 - Shared Address Space Request |
| 127.0.0.0/8 | 127.0.0.0-127.255.255.255 | RFC1122 - Reserved for loopback addresses |
| 169.254.0.0/16 | 169.254.0.0–169.254.255.255 | RFC3927 - Reserved for link-local addresses |
| 172.16.0.0/12 | 172.16.0.0-172.31.255.255 | RFC1918 - Class B private address space |
| 192.0.0.0/24 | 192.0.0.0-192.0.0.255 | RFC5736 - IETF Protocol Assignments |
| 192.0.2.0/24 | 192.0.2.0-192.0.2.255 | RFC5737 - TEST-NET-1 |
| 192.88.99.0/24 | 192.88.99.0–192.88.99.255 | RFC3068 - 6to4 Relay Anycast |
| 192.168.0.0/12 | 192.168.0.0-192.168.255.255 | RFC1918 - Class C private address space |
| 198.18.0.0/15 | 198.18.0.0–198.19.255.255 | RFC2544 - Network Interconnect Device Benchmark Testing |
| 198.51.100.0/24 | 198.51.100.0–198.51.100.255 | RFC5737 - TEST-NET-2 |
| 203.0.113.0/24 | 203.0.113.0–203.0.113.255 | RFC5737 - TEST-NET-3 |
| 224.0.0.0/4 | 224.0.0.0–239.255.255.255 | RFC3171 - Multicast |
| 240.0.0.0/4 | 240.0.0.0–255.255.255.255 | RFC1112 - Reserved for future use |
| 255.255.255.255/32 | 255.255.255.255 | RFC919 and RFC922 - Reserved for limited broadcast address |