HTTP client makes a web request. HTTP server returns a "friendly" error page.
Find out what URIs are resulting in File Not Found errors (HTTP status code 404).
ExtraHop's new multi-event trigger to the rescue! (shameless plug, if you haven't upgraded to 3.9, you should, the multi-event trigger and the new trigger editor are awesome)
To view the results of the trigger, locate a device you assigned the trigger/page/flex to above.
In the control tree should be an entry for the "HTTP 404 to URI" custom page.
Click into the page and you'll see:
- a count of File Not Found errors (HTTP status 404) for the selected time interval
- a trend of File Not Found errors over the selected time interval
Here is an example:
Viewing Results, Part 2
You can apply the trigger/page/flex included in the bundle to multiple devices and view the results via the included Flex Grid named "HTTP 404 to URI". (Remember, Flex Grids are accessed via the Summary screen)
- Download the bundle. Included in the bundle are:
- a trigger -- to inspect the HTTP request and response and store the URIs when a File Not Found error happens. Note that this trigger looks at HTTP_REQUEST and HTTP_RESPONSE with one trigger.
- a custom page -- to surface the URIs found with the trigger
- a flex grid -- to give better visibility when this trigger is deployed across multiple devices
- Assign the trigger AND custom page AND flex grid to device(s) of interest. For ease of location, all 3 items are named "HTTP 404 to URI".
- Wait for a File Not Found error.