# Run a Testnet Node

By

Travis Horn

The easiest way to interact with the Cardano network is by running your own node. Cardano provides two networks: The mainnet and the testnet. The mainnet is what you normally think about when you think about Cardano. The testnet also a real Cardano network, but ADA (called tADA on the testnet) has no real value as anyone can request it for free.

These instructions are for Linux, but you may be able to modify them according to your operating system.

Installation is a one-time process you must complete before starting a node. It will take about 10GB of storage space and synchronization will take a few hours once you get it going.

Go to https://github.com/input-output-hk/cardano-node

Under Releases, click on Cardano Node 1.33.0. The version might be different when you're reading this. Just use the latest version listed under Releases.

Under Technical Specification > Downloads, click on Hydra binaries.

Click on cardano-node-linux.

Click on cardano-node-1.33.0-linux.tar.gz to download the zipped files.

Change into the directory where the zipped files were downloaded

cd Downloads

Unzip the files

tar -xf cardano-node-1.33.0-linux.tar.gz

Make a new directory for the Cardano binary files. This could be anywhere you want.

mkdir ~/cardano-node

Move the unzipped files to that directory

mv ./* ~/cardano-node

Make sure the node directory is always in your path by adding an export in your .bashrc.

vim ~/.bashrc

export PATH="$HOME/cardano-node:$PATH"

While you're editing .bashrc, you should also add the following environment variable. This variable will be used by cardano-cli. It points to the socket your node will be running at. You may need to modify the path depending on your directory structure. I'm running my node out of the week 3 directory of the Plutus Pioneer Program. This directory already contains all of the configuration files needed to start the node

export CARDANO_NODE_SOCKET_PATH="$HOME/plutus-pioneer-program/code/week03/testnet/node.socket"

Source .bashrc to make sure the PATH is updated and CARDANO_NODE_SOCKET_PATH is set.

source ~/.bashrc

With the node installed, just do the following steps any time you want to start it.

Change into the testnet directory under week 3.

cd ~/plutus-pioneer-program/code/week03/testnet

Week 3's code contains configuration files and a helpful shell script for starting a testnet node.

Start the node using the shell script

./start-node-testnet.sh

The script contains just one command. Alternatively, you could run this command manually yourself.

cardano-node run \
  --topology testnet-topology.json \
  --database-path db \
  --socket-path node.socket \
  --host-addr 127.0.0.1 \
  --port 3001 \
  --config testnet-config.json

The first time you start the node, it will immediately start syncing with the testnet blockchain. Before you can really interact with the testnet, you'll have to wait until your node is fully synchronized. This will take a few hours.

You can see the sync progress at any time by using cardano-cli in another terminal.

The command to see sync progress requires a --testnet-magic flag with a specific number. You can find this number in the genesis configuration for the node you started.

cat testnet-shelley-genesis.json | grep Magic
  "networkMagic": 1097911063

Query to see sync progress

cardano-cli query tip --testnet-magic 1097911063

Each subsequent time you run the node, it will first push ledger state. This will take a few minutes. Then it will synchronize with the blockchain again. It should go quickly if you've ran the node recently.