If you want to start a network from scratch, you will need to start the [genesis procedure](#genesis-procedure) by creating a `genesis.json` and submit + collect the genesis transactions from the [validators](./validator-setup).
If you want to connect to an existing testnet, fetch the testnet's `genesis.json` file and copy it into the `ethermintd`'s config directory (i.e `$HOME/.ethermintd/config/genesis.json`).
Then verify the correctness of the genesis configuration file:
```bash
ethermintd validate-genesis
```
#### Add Seed Nodes
Your node needs to know how to find peers. You'll need to add healthy seed nodes to `$HOME/.ethermintd/config/config.toml`. If those seeds aren't working, you can find more seeds and persistent peers on an existing explorer.
For more information on seeds and peers, you can the Tendermint [P2P documentation](https://docs.tendermint.com/master/spec/p2p/peer.html).
The final step is to [start the nodes](./../quickstart/run_node#start-node). Once enough voting power (+2/3) from the genesis validators is up-and-running, the testnet will start producing blocks.