# Associate Discovery Rule Engines from Central to Probes in Enterprise Edition

From version 12.8.105, users can create a Discovery Rule in the Central server and associate the rule to remote probes.

### Steps to associate a Discovery Rule to a remote probe

While creating a Discovery Rule in Central, using the steps given [here](https://www.manageengine.com/network-monitoring/help/configuring-discovery-rule-engine.html), users can choose to execute the rule on the **Central** server or on a **Probe** server.

1. Go to **Settings -> Discovery -> Discovery Rule Engine** and click **Add Rule** on the top right.
2. Enter the **Name**, **Description**, **Criteria**, and **Action** for the rule, as explained [here](https://www.manageengine.com/network-monitoring/help/configuring-discovery-rule-engine.html).
3. Under **Execute At**, choose **Central** or **Probe** depending on where you want the rule to run.
4. Click **Save**.

![Discovery rule engine in OpManager: Execute At - Central or Probe](https://www.manageengine.com/sites/meweb/images/uk/network-monitoring/disc-rule-engine-1.png)

If **Execute At** is set to **Probe**, a confirmation prompt appears once the rule is saved, asking if you want to associate the rule with probes.

5. Click **Yes** on the **Associate to Probes** confirmation prompt. (Click **No** to associate the probes later from the Discovery Rule Engine listing page.)

![Discovery rule engine in OpManager: Associate to Probes confirmation](https://www.manageengine.com/sites/meweb/images/uk/network-monitoring/disc-rule-engine-2.png)

6. In the **Associate To Probes** panel, use the **Select** dropdown to filter probes, or choose from the **Available Probes** list.
7. Move the required probes to the **Selected Probes** list using the arrow buttons.
8. Click **Associate**.

![Discovery rule engine in OpManager: Associate To Probes panel](https://www.manageengine.com/sites/meweb/images/network-monitoring/images/disc-rule-engine-3.png)

You can also associate probes to a rule later, after creating it. Click **Associate** on the Discovery Rule Engine listing page, select the rule from the dropdown, then move the required probes to **Selected Probes** and click **Associate**.

**Note:**

- On the Discovery Rule Engine listing page, the **Profile Type** column indicates where each rule is set to execute: **C** denotes a Central rule, and **P** denotes a Probe rule.
- The configuration sent to a probe remains intact even if it is unselected later.

## Re-running a Discovery Rule Engine

You can [re-run a Discovery Rule](https://www.manageengine.com/network-monitoring/faq/re-run-discovery-rule-engine.html) on demand instead of waiting for its next scheduled execution. The re-run behavior depends on the rule's **Profile Type** (**C** for Central, **P** for Probe), visible on the Discovery Rule Engine listing page.

1. Go to **Settings -> Discovery -> Discovery Rule Engine**.
2. Select the rule that you want to re-run.
3. Click **Re Run**.
4. In the **Device Selection** panel, use **Filter Devices by Probe** and **Filter by** to narrow down the device list, if required.
5. Move the devices you want to run the rule on from **Available Devices** to **Selected Devices**.
6. Click **Run**.

![Discovery rule engine in OpManager: Device Selection panel for re-run](https://www.manageengine.com/sites/meweb/images/network-monitoring/images/disc-rule-engine-4.png)

- For **Central** rules, re-running works as described above; you can filter and select devices across probes as usual.
- For **Probe** rules, only one rule can be re-run at a time, and the **Device Selection** panel lists only the devices from the probe(s) the rule is associated with.

**Note:**

- If you select multiple Probe rules and click Re Run, you'll see the message: *"Only one Probe profile can be re-run at a time. Select a single profile to proceed."*
- A Probe rule must be associated with a probe before it can be re-run. If it isn't, you'll see the message: *"This profile is not associated with any probes. Associate and sync the profile before re-running."*
- If you want to re-run the rule for another probe's devices, associate the rule with that probe first, then re-run.