Relay configuration

Configure your Cardano relay node — verify config files, understand topology, and test startup.

Understanding relay vs block producer

Your relay nodes are publicly reachable and connect to the wider Cardano network. They shield your block producer (BP) from direct internet exposure. A typical setup is 1 BP + 2 relays.

The default topology.json from the release uses P2P (peer-to-peer) networking, which automatically discovers and connects to peers. After you set up your BP, you will add it as a local root peer in your relay's topology. This is covered in the launching relay section.

Verifying configuration files

If you followed the installation guide, your config files are already in ~/cnode/config/.

Verify all 6 files are present:

ls ~/cnode/config/

Expected: alonzo-genesis.json, byron-genesis.json, config.json, conway-genesis.json, shelley-genesis.json, topology.json

Updating configs manually (optional)

To fetch the latest configs after a new node release:

Mainnet

cd ~/cnode/config

curl -o config.json https://book.play.dev.cardano.org/environments/mainnet/config.json
curl -o topology.json https://book.play.dev.cardano.org/environments/mainnet/topology.json
curl -o byron-genesis.json https://book.play.dev.cardano.org/environments/mainnet/byron-genesis.json
curl -o shelley-genesis.json https://book.play.dev.cardano.org/environments/mainnet/shelley-genesis.json
curl -o alonzo-genesis.json https://book.play.dev.cardano.org/environments/mainnet/alonzo-genesis.json
curl -o conway-genesis.json https://book.play.dev.cardano.org/environments/mainnet/conway-genesis.json

ls -al

Testnet (pre-prod)

cd ~/cnode/config

curl -o config.json https://book.play.dev.cardano.org/environments/preprod/config.json
curl -o topology.json https://book.play.dev.cardano.org/environments/preprod/topology.json
curl -o byron-genesis.json https://book.play.dev.cardano.org/environments/preprod/byron-genesis.json
curl -o shelley-genesis.json https://book.play.dev.cardano.org/environments/preprod/shelley-genesis.json
curl -o alonzo-genesis.json https://book.play.dev.cardano.org/environments/preprod/alonzo-genesis.json
curl -o conway-genesis.json https://book.play.dev.cardano.org/environments/preprod/conway-genesis.json

ls -al

Quick test run

Verify the node starts before configuring the systemd service:

cardano-node run \
  --database-path /home/cardano/cnode/db \
  --socket-path /home/cardano/cnode/sockets/node.socket \
  --port 3001 \
  --config /home/cardano/cnode/config/config.json \
  --topology /home/cardano/cnode/config/topology.json

You should see the node start syncing:

Press Ctrl+C to stop the node and continue to the next section.