Detailed information about IPv4 /4 subnets
A /4 network is extremely large, allowing for millions of hosts. These are typically reserved for major infrastructure or internet service providers.
| CIDR Notation | /4 |
| Subnet Mask | 240.0.0.0 |
| Binary Subnet Mask | 11110000 00000000 00000000 00000000 |
| Total Addresses | 268,435,456 |
| Usable Hosts (Standard) | 268,435,454 |
| AWS Usable IPs | 268,435,449 |
| Azure Usable IPs | 268,435,449 |
| GCP Usable IPs | 268,435,450 |
A CIDR /4 subnet has 268,435,454 usable IP addresses for hosts. This is a relatively large subnet that can be further divided into smaller subnets if needed.
Organizations typically use subnets of this size for large-scale deployments or when planning for future growth.
Cloud providers reserve some IP addresses in each subnet for internal use, resulting in fewer usable IPs:
When planning your cloud infrastructure, consider these reserved addresses to accurately size your subnets.