On Jan 9, 2005, at 6:52 PM, Robert M. Klein wrote: > 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.
That's not true! I don't have a static address, but I connect to my home computers all the time. Check out www.dyndns.org for the method I use. My home address is dynamic, but its name stays at lml.homedns.org so I don't have to worry about what it is today. The low-tech way is to log into your router before you leave the office and copy down the WAN IP address. It's unlikely to change very often. > 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. Port 548 is for Appleshare/IP. Ports 20-21 are for ftp. But, you're far safer using scp or ssh tunneling and just leave port 22 for either. If you still have the discussion between Bill and me from a few weeks back, I showed how to do it. When you look on the Mac in your office, it will give you the local area network (LAN) address of your machine. That will likely be something like 192.168.0.n. This is the address used within your office. What you want is the wide area network address (WAN) of your router. This is the address your office has for the rest of the world. > 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? There are a couple of settings you have to tweak on your router to do this. (1) You have to tell your router to accept connections at the desired port. (2) You have to tell it which machine in your LAN will service requests at that port. For example, my router at home right now has WAN address 12.220.146.11, assigned by the InsightBB DHCP server. Through the magic supplied by www.dyndns.org, this address is associated with lml.homedns.org. Two of my machines at home are the Linux machine and my G4 Mac, which have LAN addresses 192.168.0.254 and 192.168.0.35, respectively. I told my router that outside connections on port 22 (ssh) are to be handled by the Mac and outside connections on port 80 (Web) are handled by the Linux machine. I did that by telling it to forward all WAN traffic on port 22 to LAN address 192.168.0.35 and on port 80 to LAN 192.168.0.254. Both the local machines think the traffic is coming straight from the Internet because the router just routes the packets to the right place. The remote machine gets its answer from lml.homedns.org because the router (aka the gateway) grabs the packets from the Mac and Linux machine and makes them look as though they're coming from the right place. This process is called network address translation (NAT). Thus, in my office, I type "ssh lml.homedns.org" or "ssh 12.220.146.11" to connect via ssh to my Mac at home. A Web connection to http://lml.homedns.org or http://12.220.146.11 in Safari will connect to my Linux machine. Unless you set up _both_ the open port and the port redirection in your router, it isn't going to work. You'll have to use static address on your LAN and get your router set up so the open ports point to the right machines. It's usually pretty easy to set it up, once you absorb the idea of NAT. | 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>
