[bjresta]

OK, this is surely an easy question for somebody!

I used to have my cable modem connected to my iMac. With windows file sharing on, I could use my office pc to ftp files from my home mac.

Now I have my home mac on an Airport Extreme network. Very simple settings (distribute IP addresses, share a single IP address using DHCP and NAT) so I can share the cable modem internet access with other computers at home. However, I can no longer use windows file sharing from a computer outside the network, because the address is now 10.0.1.2.

How do I set up the system (or can I) so I can use ftp to get to my home mac files from a pc outside the Airport network?

[bjresta]

Solved this with the help of a previous discussion: MacNN Forums - How do I connect my Mac from the internet when having a local number (10.0.1.x)?

Only modifications were these: to the Airport configuration, port mapping of ports 20, 21, 80, and 139 (I did both public and private) to private IP address 10.0.1.201. Make active.

Then, for the Mac I wish to access by ftp, go to Networking, then select Show AIRPORT, then select the TCP/IP tab. Select Configure Manually. Use IP address 10.0.1.201, subnet mask 255.255.255.0, router 10.0.1.1, and DNS server 10.0.1.1. Click Apply now.

Now, when you want to access your home computer from outside your network, turn on the appropriate services in the Sharing System Preference panel. However, DO NOT use the addresses that are provided there. For example, for FTP access, it says that users may access your FTP server at ftp://10.0.1.201/. THAT is NOT CORRECT. The CORRECT address will be ftp://xxx.xxx.xxx.xxx/, where xxx.xxx.xxx.xxx is the Public (WAN) IP address of your Airport Base Station, which you can obtain from the Show Summary page of your Base Station configuration using Airport Admin Utility.

Same goes for web sharing. Sites will be located at http://xxx.xxx.xxx.xxx/ or http://xxx.xxx.xxx.xxx/~user/.

It works! I made backup copies of my Network settings and my Airport config file to help in the future if there are problems.

My only questions now are related to the port mapping. Are the ports above the only ones I need to worry about? Should they be mapped for both public and private? Thanks!

[bjresta]

This solution seems to work fine without a router, but it fails when I have a router between my cable modem and Airport.

Does anyone know what other changes do I need to make because of the router?

Also, if you have time, what specific ports need to be mapped? What do they do? Does it make a difference if they are mapped public, private, or both?

Thanks a lot!