I see the IP's detail in my CPanel is 166.62.6.xx (same result as I ping from my PC to the domain).
But, there is strange IP (43.255.152.xx) is logged when this host access to my second server.
I needs to know exactly IP of my CPanel to allow only this hosting can get access to my second server.
When I allows the IP 43.255.152.xx, both servers work correctly. But 166.62.6.xx is not.
Sorry for my confusion. Which one do you mean? 166.62.6.xx or 43.255.152.xx?