> For the complete documentation index, see [llms.txt](https://stader.gitbook.io/stader/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://stader.gitbook.io/stader/ethereum/node-operator/permissionless-node-operator/node-registration-and-adding-validators/step-4-configure-stader-services/step-4.7-enable-doppelganger-protection.md).

# Step 4.7 Enable Doppelganger protection

### What is Doppelganger protection?[​](https://www.staderlabs.com/docs-v1/Ethereum/Node-operator/permissionless-node-operator/node-registration-and-adding-validators/Step%204:%20Configure%20Stader%20services/step-4.7-enable-doppelganger-protection#what-is-doppelganger-protection) <a href="#what-is-doppelganger-protection" id="what-is-doppelganger-protection"></a>

In Ethereum proof-of-stake (PoS), validators can face slashing if multiple validators operate with the same identity. Doppelganger Protection serves as a safeguard, preventing validators from being slashed and removed from the Beacon Chain in the event that a node operator unintentionally runs their validator keys on multiple machines simultaneously. [*Learn more*](https://lighthouse-book.sigmaprime.io/validator-doppelganger.html)

### How it works?[​](https://www.staderlabs.com/docs-v1/Ethereum/Node-operator/permissionless-node-operator/node-registration-and-adding-validators/Step%204:%20Configure%20Stader%20services/step-4.7-enable-doppelganger-protection#how-it-works) <a href="#how-it-works" id="how-it-works"></a>

Whenever a validator client is restarted, Doppelganger protection intentionally skips 2-3 attestations. It actively monitors the network during this process to ensure that attestations are not being transmitted using your validator keys. Ideally, there should be no attestations, indicating that no other machine is utilizing your validator keys.

After the brief waiting period, the validator client will resume its regular validation operations. However, if it detects another machine using your validator keys, it will immediately terminate and generate an error message in its log files.

In most cases, doppelganger detection results in only a few missed attestations after restarting the client. However, when you're transferring your validator to a new machine or switching to a different Beacon client, doppelganger detection becomes essential to prevent accidental double attesting and potential slashing.

{% hint style="info" %}

#### **Doppelganger protection is optional.** You can choose Yes or No based on your preference. <a href="#doppelganger-protection-is-optional-you-can-choose-yes-or-no-based-on-your-preference" id="doppelganger-protection-is-optional-you-can-choose-yes-or-no-based-on-your-preference"></a>

{% endhint %}

<figure><img src="https://res.cloudinary.com/dfupsth9n/image/upload/v1692732059/Ethereum/image_43_wwen42.png" alt=""><figcaption></figcaption></figure>