Host isolation exceptions and VPN communication (#5579)

* Add to admonition [ESS]

* Add to admonition [serverless]

* Add back accidentally deleted line

(cherry picked from commit 3886a21)

# Conflicts:
#	docs/serverless/edr-manage/host-isolation-exceptions.mdx

docs/management/admin/host-isolation-exceptions.asciidoc

@@ -12,7 +12,12 @@ Host isolation exceptions support IPv4 addresses, with optional classless inter-
 You must have the *Host Isolation Exceptions* <<endpoint-management-req,privilege>> to access this feature.
 --
 
-IMPORTANT: Each host isolation exception IP address should be a highly trusted and secure location since you're allowing it to communicate with hosts that have been isolated to prevent a potential threat from spreading.
+[IMPORTANT]
+====
+* Each host isolation exception IP address should be a highly trusted and secure location since you're allowing it to communicate with hosts that have been isolated to prevent a potential threat from spreading.
+
+* If your hosts depend on VPNs for network communication, you should also set up host isolation exceptions for those VPN servers' IP addresses.
+====
 
 Host isolation is a https://www.elastic.co/pricing[Platinum or Enterprise subscription] feature. By default, a host isolation exception is recognized globally across all hosts running {elastic-defend}. You can also assign a host isolation exception to a specific {elastic-defend} integration policy, affecting only the hosts assigned to that policy.
 

docs/serverless/edr-manage/host-isolation-exceptions.mdx

@@ -0,0 +1,75 @@
+---
+slug: /serverless/security/host-isolation-exceptions
+title: Host isolation exceptions
+# description: Description to be written
+tags: [ 'serverless', 'security', 'how-to' ]
+status: in review
+---
+
+<DocBadge template="technical preview" />
+<div id="host-isolation-exceptions"></div>
+
+You can configure host isolation exceptions (**Assets** → **Host isolation exceptions**) for specific IP addresses that <DocLink slug="/serverless/security/isolate-host">isolated hosts</DocLink> are still allowed to communicate with, even when blocked from the rest of your network. Isolated hosts can still send data to ((elastic-sec)), so you don't need to set up host isolation exceptions for them.
+
+Host isolation exceptions support IPv4 addresses, with optional classless inter-domain routing (CIDR) notation.
+
+<DocCallOut title="Requirements">
+
+You must have the appropriate user role to use this feature.
+{/* Placeholder statement until we know which specific roles are required. Classic statement below for reference. */}
+{/* You must have the **Host Isolation Exceptions** <DocLink slug="/serverless/security/endpoint-management-req">privilege</DocLink> to access this feature. */}
+
+</DocCallOut>
+
+<DocCallOut title="Important" color="warning">
+* Each host isolation exception IP address should be a highly trusted and secure location since you're allowing it to communicate with hosts that have been isolated to prevent a potential threat from spreading.
+
+* If your hosts depend on VPNs for network communication, you should also set up host isolation exceptions for those VPN servers' IP addresses.
+</DocCallOut>
+
+Host isolation requires the Endpoint Protection Complete <DocLink slug="/serverless/elasticsearch/manage-project" text="project feature"/>. By default, a host isolation exception is recognized globally across all hosts running ((elastic-defend)). You can also assign a host isolation exception to a specific ((elastic-defend)) integration policy, affecting only the hosts assigned to that policy.
+
+1. Go to **Assets** → **Host isolation exceptions**.
+1. Click **Add Host isolation exception**.
+1. Fill in these fields in the **Add Host isolation exception** flyout:
+    1. `Name your host isolation exceptions`: Enter a name to identify the host isolation exception.
+    1. `Description`: Enter a description to provide more information on the host isolation exception (optional).
+    1. `Enter IP Address`: Enter the IP address for which you want to allow communication with an isolated host. This must be an IPv4 address, with optional CIDR notation (for example, `0.0.0.0` or `1.0.0.0/24`, respectively).
+1. Select an option in the **Assignment** section to assign the host isolation exception to a specific integration policy:
+
+    * `Global`: Assign the host isolation exception to all integration policies for ((elastic-defend)).
+    * `Per Policy`: Assign the host isolation exception to one or more specific ((elastic-defend)) integration policies. Select each policy where you want the host isolation exception to apply.
+    <DocCallOut title="Note">
+    You can also select the `Per Policy` option without immediately assigning a policy to the host isolation exception. For example, you could do this to create and review your host isolation exception configurations before putting them into action with a policy.
+    </DocCallOut>
+1. Click **Add Host isolation exception**. The new exception is added to the **Host isolation exceptions** list.
+
+<div id="manage-host-isolation-exceptions"></div>
+
+## View and manage host isolation exceptions
+
+The **Host isolation exceptions** page displays all the host isolation exceptions that have been configured for ((elastic-sec)). To refine the list, use the search bar to search by name, description, or IP address.
+
+![List of host isolation exceptions](../images/host-isolation-exceptions/-management-admin-host-isolation-exceptions-ui.png)
+
+<div id="edit-host-isolation-exception"></div>
+
+### Edit a host isolation exception
+You can individually modify each host isolation exception and change the policies that a host isolation exception is assigned to.
+
+To edit a host isolation exception:
+
+1. Click the actions menu (<DocIcon type="boxesHorizontal" title="Actions menu icon" />) for the exception you want to edit, then select **Edit Exception**.
+1. Modify details as needed.
+1. Click **Save**. The newly modified exception appears at the top of the list.
+
+<div id="delete-host-isolation-exception"></div>
+
+### Delete a host isolation exception
+You can delete a host isolation exception, which removes it entirely from all ((elastic-defend)) integration policies.
+
+To delete a host isolation exception:
+
+1. Click the actions menu (<DocIcon type="boxesHorizontal" title="Actions menu icon" />) on the exception you want to delete, then select **Delete Exception**.
+1. On the dialog that opens, verify that you are removing the correct host isolation exception, then click **Delete**. A confirmation message is displayed.
+