user5798: The build instructions using nix for the cardano node are well documented, however they currently lack an option to build pre-production and preview testnet.
Does anyone know which config I could adjust to make them build these networks ?
I do know I could change configs under '/nix/store/...', but I don't think this is the right way.

user29: You can go to Cardano Testnet - Getting Started. It will explain how to set up your node for Preview and Pre-Production Testnet, complete with the configuration files.
There are also different value for each networks --testnet-magic INTEGER:

Vasil devnet : 9
Preview : 2
Pre-production : 1

This is the general steps from the docs:

Build the latest cardano-node tag (currently 1.35.3)
Download the configuration file specifically made for each Preview or Pre-Production testnet
Run your node


5798: <p>The <a href="https://github.com/input-output-hk/cardano-node/blob/master/doc/getting-started/building-the-node-using-nix.md" rel="nofollow noreferrer">build instructions using nix</a> for the cardano node are well documented, however they currently lack an option to build pre-production and preview testnet.</p>
<p>Does anyone know which config I could adjust to make them build these networks ?</p>
<p>I do know I could change configs under '/nix/store/...', but I don't think this is the right way.</p>
 29: <p>You can go to <a href="https://docs.cardano.org/cardano-testnet/getting-started" rel="nofollow noreferrer">Cardano Testnet - Getting Started</a>. It will explain <strong>how to set up your node</strong> for <strong>Preview</strong> and <strong>Pre-Production</strong> Testnet, complete with the configuration files.</p>
<p>There are also <strong>different value for each networks</strong>  <code>--testnet-magic INTEGER</code>:</p>
<ul>
<li><em>Vasil devnet</em> : <code>9</code></li>
<li><em>Preview</em> : <code>2</code></li>
<li><em>Pre-production</em> : <code>1</code></li>
</ul>
<p><strong>This is the general steps from the docs:</strong></p>
<ol>
<li>Build the latest cardano-node tag (currently 1.35.3)</li>
<li>Download the configuration file specifically made for each <strong>Preview</strong> or <strong>Pre-Production</strong> testnet</li>
<li>Run your node</li>
</ol>
