So if you can ping 172.16.110.16 from another system in your LAN and
netstat -na | grep LISTENshows port 9200 with tcp4 at *, you really should be able to connect to Elastic on that port.
That's the problem - I can't even get elasticsearch service to start if I change the network.host to anything other than 127.0.0.1. But otherwise, yes, connectivity-wise I agree with you.
root@crawler:~ # netstat -na | grep LISTEN tcp4 0 0 127.0.0.1.9200 *.* LISTEN tcp6 0 0 ::1.9200 *.* LISTEN tcp4 0 0 127.0.0.1.9300 *.* LISTEN tcp6 0 0 ::1.9300 *.* LISTEN root@crawler:~ #