Url_response probe is configured to monitor a set of url's and seems to be working however when servers physical access to the url's is blocked the probe does not raise an alarm.
Probe log shows
Feb 4 15:02:39:823 [6836] url_response: Using InternetConnect / HttpOpenRequest / HttpSendRequest to fetch https://www.someweb.com/ Feb 4 15:02:39:824 [6836] url_response: HttpQueryInfo returns 0 - Unknown error: 0 Feb 4 15:02:39:824 [6836] url_response: [test_url] debug - MyGet (https://www.someweb.com/) returns 0 Feb 4 15:02:39:824 [6836] url_response: [test_url] used 0 ms, 0 + 0 bytes, 0 bytes read Feb 4 15:02:39:824 [6836] url_response: SREPLY: status = 0(OK) ->xxx.xxx.xxx.xxx/55657
Environment
Release : 8.51
Cause
The probe uses the HttpQueryInfo function when configured to use Windows NT Authentication as the authentication method.
The monitored url is returning the 0 return code to the HttpQueryInfo function
The probe interprets the 0 return code as success and thus no alarm is raised
Resolution
Changing the probes configuration to Basic Authentication means the probe will use curl instead and allows the probe to successfully detect the URL status