# Execution Clients

{% content-ref url="/pages/G0JCzPCPOmtNoHFY9SPW" %}
[Geth](/ethereum-dev/infrastructure/client-software/execution-clients/geth.md)
{% endcontent-ref %}

{% content-ref url="/pages/vnnE8Axvk3YVm3nobgvL" %}
[Erigon](/ethereum-dev/infrastructure/client-software/execution-clients/erigon.md)
{% endcontent-ref %}

{% content-ref url="/pages/Ui4PZMWu71UFe7QaVqFy" %}
[Besu](/ethereum-dev/infrastructure/client-software/execution-clients/besu.md)
{% endcontent-ref %}

## Process - Changing Clients

1. Stop old client.
2. Disable old client.
3. Delete old client data.
4. Enable new client.
5. Start new client.

## UFW Config

Configure the firewall.

{% code title="Execution Clients" %}

```bash
EXECUTION_P2P_PORT=        # Default: 30303
EXECUTION_WS_PORT=         # Default: 8546
EXECUTION_METRICS_PORT=    # Default: 6060
EXECUTION_RPC_PORT=        # Default: 8545

sudo ufw allow ${EXECUTION_P2P_PORT} comment 'Allow Execution P2P in'
sudo ufw allow ${EXECUTION_WS_PORT} comment 'Allow Execution WS in'
sudo ufw allow ${EXECUTION_METRICS_PORT} comment 'Allow Execution Metrics in'
sudo ufw allow ${EXECUTION_RPC_PORT} comment 'Allow Execution RPC Port in'
```

{% endcode %}

## Create JWT Secret

This is now shared between all clients on the same machine.

```bash
sudo openssl rand -hex 32 | tr -d "\n" > "/tmp/jwtsecret"
sudo mv /tmp/jwtsecret /var/lib/
sudo chmod +r /var/lib/jwtsecret
```

## Execution Service Environment Variables

```bash
sudo vim /etc/default/execution-variables.env
```

{% code fullWidth="false" %}

```ini
NETWORK=                               # E.g. mainnet or holesky
EXECUTION_P2P_PORT=                    # Default: 30303
EXECUTION_MAX_PEERS=                   # Default: 50
EXECUTION_WS_ADDR=                     # e.g. 0.0.0.0
EXECUTION_WS_PORT=                     # Default: 8546
EXECUTION_RPC_ADDR=                    # e.g. 0.0.0.0
EXECUTION_RPC_PORT=                    # Default: 8545
EXECUTION_METRICS_ADDR=                # e.g. 0.0.0.0
EXECUTION_METRICS_PORT=                # Avoid 6060 clash with pprof: 6061
NGINX_PROXY_EXECUTION_METRICS_PORT=    # Unified metrics port e.g. 6062
```

{% endcode %}


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://docs.eridian.xyz/ethereum-dev/infrastructure/client-software/execution-clients.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.