External IP of the our server in the custom cloud

Wowww, new colors in th Q&A, it's amazing..... Anyway, i'm calling a external webservice from our acceptance environment to a third party. This results in a timeout, but on my local machine it works fine. The third party is using whitelisting and therefore asked our ip adresses and I gave them our company office ip and the mendix acceptance ip. I found this one by pinging the acceptance url (adviced by Mendix support). It seems that this ip is not the right one. When I do "curl -s icanhazip.com" in putty I'm receiving another ip than pinging. So I'm a little bit confused. How can I correctly retrieve the right ip of the acceptance environment?
1 answers

(simplified): We employ a three-tier architecture in the public & private cloud environments:

webserver -> app server -> db server

When you ping the URL of your app, you get the webserver. When you curl to icanhazip.com from the CLI on the appnode, you get the IP of the appnode :)