url_response does not send alarm when it has no physical access to url

Products

• DX Unified Infrastructure Management (Nimsoft / UIM)

Issue/Introduction

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