url_response does not send alarm when it has no physical access to url
Article ID: 145250
DX Infrastructure Management
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  url_response: Using InternetConnect / HttpOpenRequest / HttpSendRequest to fetch https://www.someweb.com/
Feb 4 15:02:39:824  url_response: HttpQueryInfo returns 0 - Unknown error: 0
Feb 4 15:02:39:824  url_response: [test_url] debug - MyGet (https://www.someweb.com/) returns 0
Feb 4 15:02:39:824  url_response: [test_url] used 0 ms, 0 + 0 bytes, 0 bytes read
Feb 4 15:02:39:824  url_response: SREPLY: status = 0(OK) ->xxx.xxx.xxx.xxx/55657
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
Changing the probes configuration to Basic Authentication means the probe will use curl instead and allows the probe to successfully detect the URL status