I'm on a NATed home network (10.0.0.0/8) with my cable modem having public IP 220.127.116.11 and a webserver "www" on the internal network 10.1.10.2 having port 80 forwarded by the cable modem.
Now I use a desktop client (10.1.10.3) to access www from a browser; DNS translates this to the webserver's public IP of 18.104.22.168, and the browser hangs. This happens on a variety of internal machines within my network, but works fine for clients outside of my LAN.
Also, internal clients can enter 10.1.10.2 on their browser and access the webserver just fine.
Question: Any idea why the public IP causes failure?
Note: I fixed this problem by running my own DNS (via dnsmasq) and setting "www" to 10.1.10.2, while forwarding all other names to an external nameserver.