Subnet Creation
A quick review of creating a Subnet on Avalanche - the foundation for our permissioned L1
In the Avalanche Fundamentals course, you learned how to quickly set up an L1 using the Developer Console. This section provides an in depth review of that flow, understanding what comes pre-configured in our genesis, and laying the foundation for what we will need for our Permissioned L1.
Creating a Subnet
Let's create a fresh new Subnet that we can use during this course to test all of the tools and flows for managing Permissioned L1s.
Create Builder Account & Fund Wallet
Before creating your Subnet, we recommend setting up an Avalanche Builder Account for easier access to testnet resources.
Benefits of a Builder Account:
- Faucet: C-Chain and P-Chain Testnet AVAX directly sent to your account without needing to claim
- Free Managed Testnet Infrastructure: Access free managed testnet nodes and ICM relayers for your L1
- No Docker Required: Launch and manage nodes directly from the Builder Console without local setup
After creating your account:
- Download Core Wallet if not already installed
- Set Core to Testnet mode (upper-right toggle button)
- Visit the Builder Console to claim test AVAX on both C-Chain and P-Chain
Create Subnet and Blockchain Records
Create the Subnet by issuing two transactions on the P-Chain (hence the need for test AVAX on the P-chain).
These transactions are:
CreateSubnetTx- Creates a Subnet identified by the transaction hashCreateChainTx- Adds a blockchain to the Subnet
For this guide, we will create our blockchain as an uncustomized EVM so you just need to rename it (if you want).
On Step 2: Create a Chain select the Genesis JSON tab to the right and skim through it. No need to understand it all but good to get familiar with it before the next section.
Checking requirements...
Key Parameters:
- Subnet Owner: P-chain address of your connected wallet
- Chain Name: Your blockchain's name
- VM ID: Default value
srEX...Dywhen creating with an uncustomized VM - Genesis Data: Initial blockchain configuration
Set Up Validator Node
Launch a node to track your Subnet. This node will become a validator for your Subnet, and later will be managed by the Validator Manager contract when we convert to L1.
Use our free managed testnet infrastructure - no Docker installation or AWS account required:
Checking requirements...
Managing Your Nodes
After creating nodes, you can view and manage them at the Testnet Infrastructure Console.
Managed nodes automatically shut down after 3 days. For production or extended testing, see the self-hosted option below.
Production & Extended Testing Environments
For production environments or extended testing periods, you should use Docker to run your nodes.
Docker Setup Guide:
L1 Node Setup with Docker
Configure Node Settings
Choose your node type and configure settings. The configuration preview updates in real-time.
Minimum time between blocks. Lower values = faster blocks but more network load.
Removes old state data to reduce disk usage. Storage savings depend on your L1's transaction volume. Recommended for validators and pruned RPC nodes.
Bootstrap from a recent state snapshot instead of replaying all blocks from genesis. Recommended for faster initial sync.
Enables administrative APIs. Only enable if needed and secured.
Configuration Preview
Select L1
Enter the Avalanche Subnet ID of the L1 you want to run a node for
Key Takeaways
- P-Chain Registry: All validators and blockchains are registered on the P-Chain
- Subnet Foundation: Your Subnet provides the blockchain infrastructure necessary for this course
- Managed Infrastructure or Self-Hosted: Builder Hub provides free managed testnet nodes, eliminating the need for Docker or AWS setup - you can also choose to run it yourself.
Optional Alternative: Self-Hosted Infrastructure
The free managed testnet nodes are a great option for playing around with Avalanche L1s, but are not intended for running on production environments. They are shut down automatically after 3 days. If you want to test out your production environment, running beyond 3 days, or anything more complex you should run nodes on your own infrastructure using Docker:
L1 Node Setup with Docker
Configure Node Settings
Choose your node type and configure settings. The configuration preview updates in real-time.
Minimum time between blocks. Lower values = faster blocks but more network load.
Removes old state data to reduce disk usage. Storage savings depend on your L1's transaction volume. Recommended for validators and pruned RPC nodes.
Bootstrap from a recent state snapshot instead of replaying all blocks from genesis. Recommended for faster initial sync.
Enables administrative APIs. Only enable if needed and secured.
Configuration Preview
Select L1
Enter the Avalanche Subnet ID of the L1 you want to run a node for
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