---
title: Connect to a testnet
sidebar_position: 3
Description: How to connect to a testnet
---
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# Connect to a testnet
Run Besu as an [execution client](../../concepts/node-clients.md#execution-clients) with any consensus client on the [Hoodi](https://github.com/eth-clients/hoodi), [Sepolia](https://github.com/eth-clients/sepolia), or [Ephemery](https://github.com/ephemery-testnet/ephemery-resources) testnet.
If you're using [Teku](https://docs.teku.consensys.net/en/latest/) as a consensus client, you can follow the [Besu and Teku testnet tutorial](../../tutorials/besu-teku-testnet.md).
:::note
- Sepolia is a permissioned network and you can't run a validator client on it without
[requesting to become a validator](https://notes.ethereum.org/zvkfSmYnT0-uxwwEegbCqg) first. You can connect
your consensus client using the beacon node only, without any validator duties.
- Ephemery is a single network that resets to the genesis block after a set period. The network focuses on
short-term, intensive testing use cases. This approach avoids issues like insufficient testnet funds, inactive
validators, and state bloat that long-running testnets face.
:::
## Prerequisites
- [Besu installed](../install/binary-distribution.md).
- A consensus client installed. For example, [Teku](https://docs.teku.consensys.net/en/latest/).
## Steps
### 1. Generate the shared secret
Run the following command:
```bash
openssl rand -hex 32 | tr -d "\n" > jwtsecret.hex
```
You will specify `jwtsecret.hex` when starting Besu and the consensus client. This is a shared JWT secret the clients use to authenticate each other when using the [Engine API](../../how-to/use-engine-api.md).
### 2. Generate validator keys
If you're running the consensus client as a beacon node only, skip to the [next step](#3-start-besu).
If you're also running the consensus client as a validator client, create a test Ethereum address
(you can do this in [MetaMask](https://support.metamask.io/configure/accounts/how-to-add-accounts-in-your-wallet/)).
Fund this address with testnet ETH (32 ETH and gas fees for each validator) using a faucet. See the faucets for the relevant testnet:
- [Hoodi](https://github.com/eth-clients/hoodi)
- [Sepolia](https://github.com/eth-clients/sepolia)
- [Ephemery](https://ephemery-faucet.pk910.de/)
:::note
If you can't get testnet ETH using the faucet, you can ask for help on the [EthStaker Discord](https://discord.gg/ethstaker).
:::
Generate validator keys for one or more validators using the [Hoodi Staking Launchpad](https://hoodi.launchpad.ethereum.org/), [Ephemery Staking Launchpad](https://launchpad.ephemery.dev/), or [request to become validator on Sepolia](https://notes.ethereum.org/zvkfSmYnT0-uxwwEegbCqg).
:::info
Save the password you use to generate each key pair in a `.txt` file. You should also have a `.json` file for each validator key pair.
:::
### 3. Start Besu
Run the following command or specify the options in a [configuration file](../../how-to/configure-besu/index.md):
```bash
besu \
--network=hoodi \
--rpc-http-enabled=true \
--rpc-http-host=0.0.0.0 \
--rpc-http-cors-origins="*" \
--rpc-ws-enabled=true \
--rpc-ws-host=0.0.0.0 \
--host-allowlist="*" \
--engine-host-allowlist="*" \
--engine-rpc-enabled \
--engine-jwt-secret=
```
```bash
besu \
--network=sepolia \
--rpc-http-enabled=true \
--rpc-http-host=0.0.0.0 \
--rpc-http-cors-origins="*" \
--rpc-ws-enabled=true \
--rpc-ws-host=0.0.0.0 \
--host-allowlist="*" \
--engine-host-allowlist="*" \
--engine-rpc-enabled \
--engine-jwt-secret=
```
```bash
besu \
--network=ephemery \
--rpc-http-enabled=true \
--rpc-http-host=0.0.0.0 \
--rpc-http-cors-origins="*" \
--rpc-ws-enabled=true \
--rpc-ws-host=0.0.0.0 \
--host-allowlist="*" \
--engine-host-allowlist="*" \
--engine-rpc-enabled \
--engine-jwt-secret=
```
Specify the path to the `jwtsecret.hex` file generated in [step 1](#1-generate-the-shared-secret) using the [`--engine-jwt-secret`](../../reference/cli/options.md#engine-jwt-secret) option.
You can modify the option values and add other [command line options](../../reference/cli/options.md) as needed.
### 4. Start the consensus client
Refer to your consensus client documentation to configure and start the consensus client.
:::info
If you're running a validator client, make sure you set a fee recipient address.
:::
If you're using Teku, follow the [Besu and Teku testnet tutorial](../../tutorials/besu-teku-testnet.md#5-start-teku).
### 5. Wait for the clients to sync
After starting Besu and the consensus client, your node starts syncing and connecting to peers.
```bash
{"@timestamp":"2023-02-03T04:43:49,555","level":"INFO","thread":"main","class":"DefaultSynchronizer","message":"Starting synchronizer.","throwable":""}
{"@timestamp":"2023-02-03T04:43:49,556","level":"INFO","thread":"main","class":"FastSyncDownloader","message":"Starting sync","throwable":""}
{"@timestamp":"2023-02-03T04:43:49,559","level":"INFO","thread":"main","class":"Runner","message":"Ethereum main loop is up.","throwable":""}
{"@timestamp":"2023-02-03T04:43:53,106","level":"INFO","thread":"Timer-0","class":"DNSResolver","message":"Resolved 2409 nodes","throwable":""}
{"@timestamp":"2023-02-03T04:45:04,803","level":"INFO","thread":"nioEventLoopGroup-3-10","class":"SnapWorldStateDownloader","message":"Downloading world state from peers for pivot block 16545859 (0x616ae3c4cf85f95a9bce2814a7282d75dc2eac36
cb9f0fcc6f16386df70da3c5). State root 0xa7114541f42c62a72c8b6bb9901c2ccf4b424cd7f76570a67b82a183b02f25dc pending requests 0","throwable":""}
{"@timestamp":"2023-02-03T04:46:04,834","level":"INFO","thread":"EthScheduler-Services-3 (batchPersistAccountData)","class":"SnapsyncMetricsManager","message":"Worldstate download progress: 0.08%, Peer count: 8","throwable":""}
{"@timestamp":"2023-02-03T04:48:01,840","level":"INFO","thread":"EthScheduler-Services-3 (batchPersistAccountData)","class":"SnapsyncMetricsManager","message":"Worldstate download progress: 0.23%, Peer count: 8","throwable":""}
{"@timestamp":"2023-02-03T04:49:09,931","level":"INFO","thread":"EthScheduler-Services-3 (batchPersistAccountData)","class":"SnapsyncMetricsManager","message":"Worldstate download progress: 0.41%, Peer count: 11","throwable":""}
{"@timestamp":"2023-02-03T04:50:12,466","level":"INFO","thread":"EthScheduler-Services-3 (batchPersistAccountData)","class":"SnapsyncMetricsManager","message":"Worldstate download progress: 0.61%, Peer count: 10","throwable":""}
{"@timestamp":"2023-02-03T04:51:20,977","level":"INFO","thread":"EthScheduler-Services-3 (batchPersistAccountData)","class":"SnapsyncMetricsManager","message":"Worldstate download progress: 0.75%, Peer count: 10","throwable":""}
{"@timestamp":"2023-02-03T04:51:28,985","level":"INFO","thread":"EthScheduler-Services-29 (importBlock)","class":"FastImportBlocksStep","message":"Block import progress: 180400 of 16545859 (1%)","throwable":""}
```
```bash
2022-03-21 20:43:24.355 INFO - Syncing *** Target slot: 76092, Head slot: 2680, Remaining slots: 73412, Connected peers: 8
2022-03-21 20:43:36.363 INFO - Syncing *** Target slot: 76093, Head slot: 2879, Remaining slots: 73214, Connected peers: 10
2022-03-21 20:43:48.327 INFO - Syncing *** Target slot: 76094, Head slot: 3080, Remaining slots: 73014, Connected peers: 8
2022-03-21 20:44:00.339 INFO - Syncing *** Target slot: 76095, Head slot: 3317, Remaining slots: 72778, Connected peers: 6
2022-03-21 20:44:12.353 INFO - Syncing *** Target slot: 76096, Head slot: 3519, Remaining slots: 72577, Connected peers: 9
```
If you're running the consensus client as a beacon node only, you're all set. If you're also running the consensus client as a validator client, ensure your clients are fully synced before submitting your staking deposit in the next step. This can take several days.
### 6. Stake ETH
Stake your testnet ETH for one or more validators using the
[Hoodi Staking Launchpad](https://hoodi.launchpad.ethereum.org/) or
[Ephemery Staking Launchpad](https://launchpad.ephemery.dev/).
You can check your validator status by searching your Ethereum address on the
[Hoodi explorer](https://hoodi.etherscan.io/) or
[Ephemery explorer](https://explorer.ephemery.dev/). It may take up to multiple days
for your validator to be activated and start proposing blocks.