Create a Subnet

Overview

A subnet is a range of IP addresses within your network. Instances that you launch can be contained within a subnet in your network.

After setting up a network, you can configure multiple subnets. Then you can launch an instance in any subnet that you have created.

Security groups can be applied to subnets to add an additional layer of security for instances in a network. 

Prerequisites

• 'security_manager' user role privilege

Steps

1. Go to Manage > Network > select a Network.
2. Click on the Subnets tabs.
3. Click New Subnet.

• Name: Name of the subnet. You can create up to 20 subnets in a VPC.
• Description: A user-defined description for the subnet. Optional.
• Datacenter: This corresponds to Availability Zone in AWS. Resources in Datacenters are logically grouped and are fault isolated from other resources in other Datacenters.
• Network: The name of the network and CIDR block of your network. 
• CIDR Block: IP Range for the subnet. The subnets CIDR block can be the same as the VPC's CIDR block or a subset of VPC's CIDR block. If you create more than one subnet in a VPC, the subnets CIDR blocks must not overlap. The smallest subnet you can create uses a /28 netmast (16 IP addresses) and the largest uses a /16 netmask (65,536 IP addresses). 

4. Click Create.
5. The subnet will be created. It's state will be "pending" and, after a few moments, will be "available" which means you can assign the subnet to an instance. 

When creating a subnet, you have to specify a subnet within the range of the CIDR block of the network or you will receive an error. For example, if your network is 10.0.0.0/16, the range of subnets you create should be between 10.0.0.0/16 - 10.0.255.240/28. If you already have a CIDR block range defined, you cannot create a subnet with a range that overlaps. So if you have a subnet with a CIDR block of 10.0.0.0/16, you will not be able to create a CIDR block of 10.0.3.0/24.

See also

• Networks
• Edit a Subnet
• Delete a Subnet