I believe you will have to open (forward) any ports on the office router for the services you want to use. Personal File Sharing uses port 548; FTP uses 20 and 21. You would also need to turn on those services in the Sharing preferences pane for the Mac you want to access (sounds like you've already done that part).
Assuming that the office router has a browser-accessible interface, you would access the router through your browser on the Mac at work at whatever local IP address it is using (usually 192.168.x.1). Then make note of the wide-area network (WAN) IP address that the router is using (we will hope, and assume, that it is a static IP address). That WAN IP address is the one you will have to input when accessing any computers behind that router from outside locations. While in the router, also make note of its subnet mask and the DNS numbers (probably two of them) that the router uses. Your router's interface should allow you, assuming you have password access to it, to "open" or "forward" specific ports to specific computers that sit behind that router. But before you do that, you will want to assign the work computer that you want to access a manual local IP (in the range of 192.168.0.x, or whatever subnet your router uses -- if your router uses 192.168.0.1, you might assign the computer 192.168.0.2). You will do that by opening the Network preference pane, clicking the "TCP/IP" tab and choosing "Manually" (rather than "Using DHCP") and typing in the IP you want to assign to that computer. You will also need to enter in the subnet mask number, the router's local IP (192.168.x.1, probably) and the DNS numbers that you noted from your router's settings. Once you manually set your computer's local IP, go back to the router interface and its "port forwarding" screen. This will allow you to open specific ports to the local computer to which you manually assigned an IP number. It should be pretty obvious how to do this. If you used 192.168.0.2 for the computer, for that IP number you would forward port 548 for personal file sharing and the 20-21 range for FTP. When you want to access personal file sharing on that computer from your home computer, enter the WAN IP address that your router uses (it will not, and cannot, be in the 192.168.x.x) when you are asked to enter the server's address. If everything was done right, that should send to your work router a request to communicate over port 548 with any computer behind that router that allows access through that port. Exactly what would happen next, I don't know, as I've never tried that, but I would imagine that your work computer would asked you for a username and password. Once correctly provided, it should mount on your home computer's desktop just like it would if you logged on to it on a local network. > Lee helped with this about a year ago but I have never gotten it to > work. > > I want to connect via the internet to my computer at the office, which > is > connected via DSL (BellSouth). There is a Netopia router and we have a > static IP address that I was told by them was necessary in order to > connect > this way. The office Mac has Personal File Sharing on and FTP on, > and, I > think, the firewall has port 548 open. According to the Apple support > stuff > I can find, when you highlight FTP Access in Sharing, the IP address > given > is supposed to tell you the one to input on the other end. All I get > is the > 192.168.0.? number, which is just the local network address, I think. > Its > the same address that DHCP comes up with, too. When I put it in from > home > (Go>Connect to Server), I get a query that asks for id and password. > I have > tried the id and password for my office Mac and for the router, and > both > come back and say it?s wrong. I even tried it with no id and password > input, also to no avail. > > I am running 10.3.7 at both ends. > > Somewhere along the line I was told that Port 21 had to be open on the > router, but BellSouth told me that it was open. How do I know? If I > go > into the router, what setting am I looking for? > > Any help will be very much appreciated. > > Thanks, > Robert | The next meeting of the Louisville Computer Society will | be January 25. The LCS Web page is <http://www.kymac.org>. | List posting address: <mailto:macgroup at erdos.math.louisville.edu> | List Web page: <http://erdos.math.louisville.edu/macgroup>
