Check_MK cannot connect after installation

Hi Andreas,
We have installed version# 1.4.16
It was provided from here: Download Checkmk for free | Checkmk
If there is an advanced version to work with, I would happily install it.
But, even this version installed just fine. I configured iP address & enabled Web configuration & SSH. LAN status shows UP & green. But I cannot ping or reach the IP address. Which is why I cannot control the site from the web.
Anything I am doing wrong here?

Thanks
Arindam