Help Center/ Virtual Private Cloud/ User Guide/ VPC and Subnet/ Subnet/ Viewing the Number of Available IP Addresses in a Subnet
Updated on 2025-09-24 GMT+08:00

Viewing the Number of Available IP Addresses in a Subnet

Scenarios

After a VPC is created, its available IP addresses is the sum of those in its subnets. After a subnet is created, you can query the number of available IP addresses on the subnet details page. The number of available IP addresses in a subnet helps you allocate IP addresses and prevent service interruptions caused by IP address exhaustion.

Notes and Constraints

After a subnet is created, the following IP addresses are reserved by the system and cannot be assigned to any instance. For example, in a subnet with CIDR block 192.168.0.0/24, the following IP addresses are reserved by default:

  • 192.168.0.0: Network ID. This address is the beginning of the private IP address range and will not be assigned to any instance.
  • 192.168.0.1: The gateway address of the subnet.
  • 192.168.0.253: Reserved for the system interface. This IP address is used by the VPC for external communication.
  • 192.168.0.254: DHCP service address.
  • 192.168.0.255: Network broadcast address.

These IP addresses are for reference only. The system assigns reserved IP addresses based on your subnet settings. All other IP addresses in the subnet can be assigned to instances.

Procedure

  1. Go to the subnet list page.
  2. In the subnet list, locate the target subnet and click its name.

    The subnet details page is displayed.

  3. On the Summary tab, check the value of Available IP Addresses.
    Figure 1 Viewing the number of available IP addresses