InformationSets the timeout for an HTTP session before the security appliance terminates it.
Limiting session timeout prevents unauthorized users from using abandoned sessions to perform malicious activities.
SolutionFrom the Firepower Management Center:
Step 1. Navigate to Devices > Platform Settings
Step 2. Either edit the platform settings policy which exists as you click the pencil icon beside the policy or create a new FTD policy as you click New Policy. Select the type as Firepower Threat Defense.
Step 3. As you navigate to the HTTP section, a page appears as shown in the image.
Enable HTTP server: Enable this option to make to enable HTTP server on the FTD.