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# Creating a Private Network using Ethash (Proof of Work) Consensus Protocol
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A private network provides a configurable network for testing. By configuring a low difficulty and enabling
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mining, blocks are created quickly.
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You can test multi-block and multi-user scenarios on a private network before moving to one of the public testnets.
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!!!important
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An Ethereum private network created as described here is isolated but not protected or secure.
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We recommend running the private network behind a properly configured firewall.
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## Prerequisites
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[Pantheon](../Installation/Install-Binaries.md)
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[Curl (or similar web service client)](https://curl.haxx.se/download.html)
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## Steps
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The steps to create a private network using Ethash are displayed on the right.
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### 1. Create Folders
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Each node requires a data directory for the blockchain data. When the node is started, the node key is saved in this directory.
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Create directories for your private network, each of the three nodes, and a data directory for each node:
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```bash
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Private-Network/
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├── Node-1
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│ ├── data
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├── Node-2
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│ ├── data
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└── Node-3
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├── data
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```
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### 2. Create Genesis File
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The genesis file defines the genesis block of the blockchain (that is, the start of the blockchain).
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The genesis file includes entries for configuring the blockchain such as the mining difficulty and initial
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accounts and balances.
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All nodes in a network must use the same genesis file. The [network ID](../Configuring-Pantheon/NetworkID-And-ChainID.md)
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defaults to the `chainID` in the genesis file. The `fixeddifficulty` enables blocks to be mined quickly.
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Copy the following genesis definition to a file called `privateNetworkGenesis.json` and save it in the `Private-Network` directory:
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```json
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{
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"config": {
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"constantinoplefixblock": 0,
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"ethash": {
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"fixeddifficulty": 1000
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},
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"chainID": 1981
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},
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"nonce": "0x42",
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"gasLimit": "0x1000000",
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"difficulty": "0x10000",
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"alloc": {
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"fe3b557e8fb62b89f4916b721be55ceb828dbd73": {
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"privateKey": "8f2a55949038a9610f50fb23b5883af3b4ecb3c3bb792cbcefbd1542c692be63",
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"comment": "private key and this comment are ignored. In a real chain, the private key should NOT be stored",
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"balance": "0xad78ebc5ac6200000"
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},
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"f17f52151EbEF6C7334FAD080c5704D77216b732": {
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"privateKey": "ae6ae8e5ccbfb04590405997ee2d52d2b330726137b875053c36d94e974d162f",
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"comment": "private key and this comment are ignored. In a real chain, the private key should NOT be stored",
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"balance": "90000000000000000000000"
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}
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}
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}
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```
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!!! warning
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Do not use the accounts in the genesis file above on mainnet or any public network except for testing.
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The private keys are displayed so the accounts are not secure.
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### 3. Start First Node as Bootnode
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Start Node-1:
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```bash tab="MacOS"
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pantheon --data-path=data --genesis-file=../privateNetworkGenesis.json --bootnodes --miner-enabled --miner-coinbase fe3b557e8fb62b89f4916b721be55ceb828dbd73 --rpc-http-enabled --host-whitelist=* --rpc-http-cors-origins="all"
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```
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```bash tab="Windows"
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pantheon --data-path=data --genesis-file=..\privateNetworkGenesis.json --bootnodes --miner-enabled --miner-coinbase fe3b557e8fb62b89f4916b721be55ceb828dbd73 --rpc-http-enabled --host-whitelist=* --rpc-http-cors-origins="all"
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```
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The command line specifies:
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* No arguments for the [`--bootnodes`](../Reference/Pantheon-CLI-Syntax.md#bootnodes) option because this is your bootnode.
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* Mining is enabled and the account to which mining rewards are paid using the [`--miner-enabled`](../Reference/Pantheon-CLI-Syntax.md#miner-enabled)
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and [`--miner-coinbase`](../Reference/Pantheon-CLI-Syntax.md#miner-coinbase) options.
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* JSON-RPC API is enabled using the [`--rpc-http-enabled`](../Reference/Pantheon-CLI-Syntax.md#rpc-http-enabled) option.
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* All hosts can access the HTTP JSON-RPC API using the [`--host-whitelist`](../Reference/Pantheon-CLI-Syntax.md#host-whitelist) option.
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* All domains can access the node using the HTTP JSON-RPC API using the [`--rpc-http-cors-origins`](../Reference/Pantheon-CLI-Syntax.md#rpc-http-cors-origins) option.
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!!! info
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The miner coinbase account is one of the accounts defined in the genesis file.
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When the node starts, the [enode URL](../Configuring-Pantheon/Node-Keys.md#enode-url) is displayed.
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Copy the enode URL to specify Node-1 as the bootnode in the following steps.
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### 4. Start Node-2
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Start another terminal, change to the `Node-2` directory and start Node-2 specifying the Node-1 enode URL copied when starting Node-1 as the bootnode:
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```bash tab="MacOS"
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pantheon --data-path=data --genesis-file=../privateNetworkGenesis.json --bootnodes=<Node-1 Enode URL> --p2p-port=30304
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```
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```bash tab="Windows"
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pantheon --data-path=data --genesis-file=..\privateNetworkGenesis.json --bootnodes=<Node-1 Enode URL> --p2p-port=30304
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```
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The command line specifies:
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* Different port to Node-1 for P2P peer discovery using the [`--p2p-port`](../Reference/Pantheon-CLI-Syntax.md#p2p-port) option.
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* Enode URL for Node-1 using the [`--bootnodes`](../Reference/Pantheon-CLI-Syntax.md#bootnodes) option.
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* Data directory for Node-2 using the [`--data-path`](../Reference/Pantheon-CLI-Syntax.md#data-path) option.
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* Genesis file as for Node-1.
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### 5. Start Node-3
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Start another terminal, change to the `Node-3` directory and start Node-3 specifying the Node-1 enode URL copied when starting Node-1 as the bootnode:
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```bash tab="MacOS"
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pantheon --data-path=data --genesis-file=../privateNetworkGenesis.json --bootnodes=<Node-1 Enode URL> --p2p-port=30305
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```
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```bash tab="Windows"
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pantheon --data-path=data --genesis-file=..\privateNetworkGenesis.json --bootnodes=<Node-1 Enode URL> --p2p-port=30305
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```
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The command line specifies:
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* Different port to Node-1 and Node-2 for P2P peer discovery.
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* Data directory for Node-3 using the [`--data-path`](../Reference/Pantheon-CLI-Syntax.md#data-path) option.
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* Bootnode and genesis file as for Node-2.
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### 6. Confirm Private Network is Working
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Start another terminal, use curl to call the JSON-RPC API [`net_peerCount`](../Reference/JSON-RPC-API-Methods.md#net_peercount) method and confirm the nodes are functioning as peers:
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```bash
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curl -X POST --data '{"jsonrpc":"2.0","method":"net_peerCount","params":[],"id":1}' localhost:8545
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```
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The result confirms Node-1 (the node running the JSON-RPC service) has two peers (Node-2 and Node-3):
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```json
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{
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"jsonrpc" : "2.0",
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"id" : 1,
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"result" : "0x2"
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}
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```
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## Next Steps
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Import accounts to MetaMask and send transactions as described in the [Private Network Quickstart Tutorial](Private-Network-Quickstart.md#creating-a-transaction-using-metamask)
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!!! info
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Pantheon does not implement [private key management](../Using-Pantheon/Account-Management.md).
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Send transactions using `eth_sendRawTransaction` to [send ether or, deploy or invoke contracts](../Using-Pantheon/Transactions/Transactions.md).
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Use the [JSON-RPC API](../JSON-RPC-API/Using-JSON-RPC-API.md).
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Start a node with the [`--rpc-ws-enabled`](../Reference/Pantheon-CLI-Syntax.md#rpc-ws-enabled) option and use the [RPC Pub/Sub API](../Using-Pantheon/RPC-PubSub.md).
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## Stop Nodes
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When finished using the private network, stop all nodes using ++ctrl+c++ in each terminal window.
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!!!tip
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To restart the private network in the future, start from [3. Start First Node as Bootnode](#3-start-first-node-as-bootnode).
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