Pantheon specifies the genesis configuration, and sets the network ID and bootnodes when connecting
to [Mainnet](#run-a-node-on-ethereum-mainnet), [Goerli](#run-a-node-on-goerli-testnet), [Rinkeby](#run-a-node-on-rinkeby-testnet), and [Ropsten](#run-a-node-on-ropsten-testnet).
When [`--dev-mode`](../Reference/Pantheon-CLI-Syntax.md#dev-mode) is specified, Pantheon uses the development mode genesis configuration.
The genesis files defining the genesis configurations are in the [Pantheon source files](https://github.com/PegaSysEng/pantheon/tree/master/config/src/main/resources).
To define a genesis configuration, create a genesis file (for example, `genesis.json`) and specify the file
using the [`--genesis`](../Reference/Pantheon-CLI-Syntax.md#genesis) option.
## Confirm Node is Running
If you have started Pantheon with the [`--rpc-enabled`](../Reference/Pantheon-CLI-Syntax.md#rpc-enabled) option, use [cURL](https://curl.haxx.se/) to
call [JSON-RPC API methods](../Reference/JSON-RPC-API-Methods.md) to confirm the node is running.
!!!example
*`eth_chainId` returns the chain ID of the network.
```bash
$ curl -X POST --data '{"jsonrpc":"2.0","method":"eth_chainId","params":[],"id":1}' 127.0.0.1:8545
```
*`eth_syncing` returns the starting, current, and highest block.
```bash
$ curl -X POST --data '{"jsonrpc":"2.0","method":"eth_syncing","params":[],"id":1}' 127.0.0.1:8545
```
For example, after connecting to mainnet `eth_syncing` will return something similar to:
Alternatively, use the following [configuration file](../Configuring-Pantheon/Using-Configuration-File.md) and `--bootnodes` on the command line to start a node with the same options as above: