| 0.0.0.0/8 | Software | Current network[1] (only valid as source address). |
| 10.0.0.0/8 | Private network | Used for local communications within a private network.[2] |
| 100.64.0.0/10 | Private network | Shared address space[3] for communications between a service provider and its subscribers when using a carrier-grade NAT. |
| 127.0.0.0/8 | Host | Used for loopback addresses to the local host.[1] |
| 169.254.0.0/16 | Subnet | Used for link-local addresses[4] between two hosts on a single link when no IP address is otherwise specified, such as would have normally been retrieved from a DHCP server. |
| 172.16.0.0/12 | Private network | Used for local communications within a private network.[2] |
| 192.0.0.0/24 | Private network | IETF Protocol Assignments.[1] |
| 192.0.2.0/24 | Documentation | Assigned as TEST-NET-1, documentation and examples.[5] |
| 192.88.99.0/24 | Internet | Reserved.[6] Formerly used for IPv6 to IPv4 relay[7] (included IPv6 address block 2002::/16). |
| 192.168.0.0/16 | Private network | Used for local communications within a private network.[2] |
| 198.18.0.0/15 | Private network | Used for benchmark testing of inter-network communications between two separate subnets.[8] |
| 198.51.100.0/24 | Documentation | Assigned as TEST-NET-2, documentation and examples.[5] |
| 203.0.113.0/24 | Documentation | Assigned as TEST-NET-3, documentation and examples.[5] |
| 224.0.0.0/4 | Internet | In use for IP multicast.[9] (Former Class D network). |
| 240.0.0.0/4 | Internet | Reserved for future use.[10] (Former Class E network). |
| 255.255.255.255/32 | Subnet | Reserved for the "limited broadcast" destination address.[1][11] |