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Create a Subnet

Before You Begin​

  • You need at least one existing VPC (General or Specific type).
  • Determine in advance the CIDR address range you want to use. The CIDR of the new subnet must not overlap with any existing subnet in the same VPC.
  • Decide on the subnet type: Routed (can reach the Internet) or Isolated (internally isolated).

Steps​

Step 1: Navigate to the Subnets page​

  1. Log in to the FPT Cloud Portal.
  2. Select the VPC in which you want to create a subnet.
  3. In the VPC's left menu, select Network → Subnets.

Step 2: Open the Create Subnet form​

Click the "Create subnet" button in the top-right corner of the list page.

Create Subnet Form

Step 3: Enter a Subnet name​

Fill in the Name field with a meaningful name for easy identification later. Name is a required field.

Example: subnet-web-frontend, subnet-db-private

Step 4: Select the Subnet type​

Select one of the two options in the Type field:

OptionDescription
RoutedThe subnet routes traffic to the Internet via NAT gateway. Use this when virtual machines need outbound connectivity (downloading updates, calling external APIs, etc.).
IsolatedThe subnet has no Internet routing. Virtual machines communicate only within the VPC. Use this for databases, caches, or any workload that requires network isolation.

Step 5: Enter the Network address (CIDR)​

Enter the network address range in the Network address (CIDR) field.

Example: 192.168.1.0/24

Important note: The CIDR must not overlap with any other subnet in the same VPC. If it overlaps, the system will display an error and reject the subnet creation.

Step 6: Enter the Gateway address​

Enter the gateway address in the Gateway IP field. The gateway is typically the first usable address in the CIDR range.

Example: For CIDR 192.168.1.0/24, the gateway is typically 192.168.1.1

Step 7: Configure optional settings​

The following fields are optional and can be left blank:

  • Static IP pool — Specify a sub-range of IP addresses within the CIDR for static allocation to virtual machines. If left blank, the system manages the entire address range automatically.
  • Primary DNS — The primary DNS server address that virtual machines in the subnet will use.
  • Secondary DNS — A backup DNS server address (used only when Primary DNS is unresponsive).

Step 8: Add tags (optional)​

If you want to organize or categorize the subnet with labels, click "Add tag" and enter the appropriate key–value pair.

Step 9: Confirm creation​

Click the confirm button (typically "Create" or "Confirm") to complete the process. The new subnet will appear in the list within a few seconds.

After Successful Creation​

  • The new subnet appears in the list with full details: name, CIDR, gateway, DNS, and creation time.
  • You can proceed to create virtual machines and assign this subnet as the network for those machines.
  • If you selected the Isolated type, virtual machines in the subnet will not be able to connect to the Internet — this is normal, by-design behavior.