welcome!
point is: the computer running HFS doesn't have an internet address, while the router/modem or what's in between does.
You have to tell the router to act as a bridge, and forward requests coming from home to the right computer.
from the FAQ
- I can locally access my HFS server, but when my friend tries to access my HFS server, he gets the "Unable to connect" or "The page cannot be displayed" error. Why?
This problem is most likely caused by a router or a firewall. If you are currently behind a network, make sure that the correct port is forwarded to your computer. (Instructions are available at
http://www.portforward.com/ .) Additionally, try disabling software firewalls, or enabling HFS server permissions, if applicable. To simplify this process, use the Self Test feature in HFS. Self Test confirms whether your HFS server is working properly, and is very trustworthy.