We want to check some web sites availability from a special server (named "A" for instance) which has access to internet via a proxy server (named "B" for instance). so in PRTG server (named "C" for instance)we added a http sensor for server "A" and in "Proxy settings for http sensors" entered Name & port of server"B" (there is no need for Credentials).after all HTTP sensor is "Down" with this Error message: HTTP/1.1 502 Proxy Error ( Forefront TMG denied the specified Uniform Resource Locator (URL). )
beside this our proxy server(B) is TMG & all needed rules are added.
The Rule which makes Sensor Status "Down" From: Server"A" To: All networks Users: All users Protocols: HTTP & HTTPs
PRTG Server(C) has no access to internet via the proxy but when it is allowed to connect to internet via the proxy server, sensor status changes to "UP".
The Rule which makes Sensor Status "UP": From: PRTG Server(C) To: All networks Users: All users Protocols: HTTP & HTTPs
it seems that it checks that URL from PRTG Server(C) through Proxy. how can we check that website from Server A not PRTG?
Hello AJamshidi,
thank you for your post.
Please note that all monitoring requests will be sent from the PRTG Probe on which the sensor was created, in your case all monitoring requests will income from PRTG Server(C) by default. To monitor the connectivity as 'experienced' on Server "A" the Remote Probe software needs to be installed there.
There's an explanation on how "monitoring requests work" here.
You may also find more information on monitoring and remote probes on the following manual pages:
Best Regards,
Apr, 2016 - Permalink