Learn and Enable the WAF's Monitor Mode

Overview

You can use this document to learn about and enable the Monitor mode for an existing site with a WAF.

Note:

If you have not enabled the WAF for a site, then see Enable WAF on an Existing Site.

There are 3 WAF modes: 

• Protect
• Monitor
• Off

You can use the Monitor mode to temporarily test the WAF's behavior so that you can adjust the WAF before you fully Protect the WAF. 

With the exception of protection against Application Layer DDoS Attacks, while in the Monitor mode, the WAF (including custom WAF rules) does not perform any action against requests. Instead, the WAF logs requests that would have been blocked or sanctioned under the Protect mode. 

• To learn more about the WAF's protection against Application Layer DDoS Attacks, see Learn About the StackPath WAF.

Review sample scenario

For example, a cURL request without any header modification flags will trigger the Invalid User Agent Prevention policy. 

If the WAF is in Protect mode, then the request will receive a 403 status code: 

  curl -I https://c8k3p3x4.stackpathcdn.com
  HTTP/2 403 
  date: Mon, 25 Mar 2019 20:38:48 GMT

If the WAF is in Monitor mode, then the request will receive a 200 status code. 

  curl -I https://c8k3p3x4.stackpathcdn.com
  HTTP/2 200
  date: Mon, 25 Mar 2019 20:40:37 GMT

Additionally, while in Monitor mode, the WAF will log a request.  

Enable WAF Monitor mode 

You can use these instructions to enable the Monitor mode for sites that already have the WAF enabled. 

1. In the StackPath Control Portal, in the left-side navigation, click Sites. 
2. Locate and select the desired site.
   • This action will refresh the portal. 
3. In the left-side navigation, click WAF. 
4. In the top, right corner of the screen, next to WAF Mode, in the drop-down menu, select Monitor. 
   • To confirm, in the left-side navigation, click Analytics, and then select the WAF tab. Monitor Mode will display next to Web Application Firewall Requests. 

After you enable Monitor mode, StackPath recommends that you review the results and adjust your WAF settings. To learn more, see Enable WAF on an Existing Site, and then go to Step 3: View WAF results.