Need help with SAM HTTP monitor

Hello All,

I am trying to setup a http monitor in SAM that is dynamic and runs on different hosts. When i use Node.Sysname variable i am getting the below error.

URL:

http://${Nodes.SysName}:${PORT}/servlet/raApp

ERROR: 

[Errno -2] Name or service not known

But when i run with actual host name i am able to get it running successfully. This is not working even with $IP variable. Can someone please help me with this?