You are proving that you can lookup the DNS name to give you an IP address and indeed you may be sending packets and requests out from your server, but zero packets received means:-
- The target IP is not active
- There is no route to the target IP (you mention google.com but then a 172.x.x.x private address)
- Your outbound IP tables may filter them out
- Your network devices may filter them out
- The target IP may ignore you
- The target IP may try to respond but your public-facing proxy may filter them out
- The target IP may try to respond but your internal network devices may filter them out
- The target IP may try to respond but your inbound IP tables may filter them out
A ping is one type of packet, so it does not guarantee that you will actually be able to hold a conversation with the target address.
What is your eventual intention for which I presume that this is a step? Perhaps there is a better way to be monitoring what it is that you really need.
Kind regards,
Robin