Configure subnets

A subnet is a range of IP addresses within a Virtual Private Cloud (VPC). This guide shows you how to create, view, and delete subnets using the evroc CLI.

Prerequisites

  • Access to an evroc organization and project.
  • evroc CLI installed and configured.
  • A VPC in your project (see Configure VPCs).

View subnets

List all subnets in your project:

evroc networking subnet list

View details of a specific subnet:

evroc networking subnet get my-subnet

The output shows the subnet's stack type, IPv4 and IPv6 CIDR blocks, and parent VPC.

Create a subnet

When you create a subnet, you must specify its stack type, zone, and (for dual-stack subnets) its IPv4 CIDR block.

Create a dual-stack subnet

A dual-stack subnet supports both IPv4 and IPv6 addresses. You must specify the IPv4 CIDR block.

evroc networking subnet create my-subnet \
  --vpc=my-vpc \
  --zone=se-sto-a \
  --stack-type=dual-stack \
  --ipv4-cidr-block=10.0.99.0/24

The subnet is created with:

  • The specified IPv4 CIDR block.
  • A /64 IPv6 CIDR block allocated automatically from the parent VPC's IPv6 range.

Create an IPv6-only subnet

An IPv6-only subnet has no IPv4 CIDR block. All VMs in this subnet must also be IPv6-only.

evroc networking subnet create my-subnet \
  --vpc=my-vpc \
  --zone=se-sto-a \
  --stack-type=ipv6-only

The subnet receives a /64 IPv6 CIDR block allocated automatically from the parent VPC's IPv6 range.

Subnet CIDR constraints

IPv4 CIDR blocks for subnets must follow these rules:

  • The subnet CIDR must be within the parent VPC's IPv4 CIDR block
  • The subnet size can be between /16 and /29
  • Subnet CIDRs within the same VPC must not overlap

For example, if your VPC has 10.0.0.0/16, valid subnet CIDRs include 10.0.1.0/24, 10.0.2.0/24, and 10.0.3.0/29.

Delete a subnet

Delete a subnet that has no VMs:

evroc networking subnet delete my-subnet

Important: You can't delete a subnet that contains VMs. Delete or move all VMs from the subnet first.

Understanding VM IP addresses

When you create a VM, it's automatically assigned an IP address from the subnet in its zone. For example, a VM using the subnet default-se-sto-a gets an IP from 10.0.1.0/24. You can view a VM's IP addresses using the VM get command:

evroc compute virtualmachine get myvm

Look for the privateIPv4Address and ipv6Address fields in the output.

Next steps