Remote file sharing

Question

I am currently in USA and am trying to connect to my mac in UK to get a large file. I have followed the support page instructions but have been unable to connect. Any suggestions.

Answer 1

Hi - that really depends on your son's router. Every router that I know of has a webpage to do configuration stuff. Your son would access it by typing something like http://192.168.0.1 in Safari. If he looks in his System Preferences Network TCP/IP stuff, the IP address of the router as listed there is what he needs to use in place of my 192.168.0.1 example.
Once there, there are one, maybe three, things that he will probably have to do.
Step 1: First, he'll need to turn on file sharing in his Mac as discussed in my previous post. Then, he'll have to navigate his way to a "port forwarding" configuration webpage on his router. On my ActionTec all-in-one combo DSL modem + wired&wireless access point + router, I go into "Advanced Settings" then there is a link to "port forwarding." Once there, you would enter a port range of 548 to 548, protocol is TCP, and your son's computer's name or its intranet (192.168.x.x or 10.x.x.x) IP address. Save changes and reboot router.
If it doesn't let him do that, it may be because the router doesn't track computers on its LAN by their ethernet port's or Airport wireless' MAC address, but rather by IP address, so it will only let him forward ports to machines that don't have a dynamically assigned IP address by the router. If that's the case, on to step 2:
Step 2: there should be a link in the advanced setup junk for DHCP Server in one of the router's configuration webpages. He should be able to set a range of DHCP-assigned IP addresses. Does this range of numbers run the whole gamut of the whole subnet? That is to say, if the subnet mask is 255.255.255.0, does the beginning and ending IP addresses run from, say, 192.168.0.2 to 192.168.0.254? If so, restrict the range to something smaller, like 192.168.0.101 to 192.168.0.254. Note: Don't mess with the first three numbers if his are different than my example here, i.e., the 192.168.0 part, only change the last number. I will continue to use the 192.168.0 in my examples, for example only. Leave the subnet alone. Once he's made this change, save changes and reboot router.
In his Mac's System Preferences Network TCP/IP, choose "Using DHCP with manual address" and manually enter an IP address for his Mac. Using my example, choose something between 192.168.0.2 and 192.168.0.100, i.e., something outside the DHCP assigned address range (BTW, x.x.x.254 is as big as the numbers can be, so he needs to pick something less than that x.x.x.101 number). Then apply the change.
If we even had to do step 2, we're getting close to finishing up now. Time for Step 3.
Step 3: Go back into the router's "port forwarding" configuration webpage. Now that he has a range of static IP addresses available (static are 192.168.0.2 - 192.168.0.100 since he specified the range of dynamic addresses to be 192.168.101 -192.168.0.254), he should be able to do Step 1 now.
Post file retrieval: Once you have successfully retrieved the file, your son needs to go back into the port forwarding configuration webpage and delete that port forward. People might disagree with me on this, but it is my understanding that AFP file transfers are not encrypted, so however unlikely, a sniffer at the right place at the right time could have intercepted your username and password and could then have AFP upload and download privileges with your son's computer. Or hack his way in via that open port and do other nasty stuff to him or to others, using his computer to do it. That's why I tunnel my AFP stuff through secure shell, in order to encrypt the username/password, and data transfer, but if you're not comfortable with Terminal.app, it might be perceived to be a bit daunting to set up.
Once the port forward is deleted, have him save changes in his router and reboot router. And your son should go back into his Mac's System Preferences Network TCP/IP, and choose "Using DHCP" (no longer with manual address) and apply changes. Also, he'll need to pay a visit to his System Preferences Sharing Services and uncheck the "file sharing" checkbox and make sure the firewall is still ON.
There is no harm in leaving the range of assigned DHCP addresses to be the x.x.x.101 to x.x.x.254 range in the router, unless your son has more than 154 computers and networked peripherals attached to his home LAN. However, if desired, he can go back to the DHCP Server configuration webpage and change it back to the way it was.
Also, I suppose it is possible that every time he reboots his router, that his ISP could conceivably assign him a new public IP address. He'll need to check that out and if it changes on him, he'll need to text IM you with the new public IP address. He can get it from http://whatsmyipaddress.com.
All this having been said, http://portforward.com/cports.htm can provide him with some guidance for forwarding ports on his specific make and model of router (if it is listed), although I don't see anything specific there for forwarding ports for Apple File Protocol, AFP, or port 548. So just pick something like Apple Remote Desktop and follow those general guidelines for your son's specific router, just don't use the port numbers they say, use port 548 for TCP instead.
And lastly, if your son's home network architecture looks like this:
    internet<-->modem<--> (non-wireless) router<-->Airport Extreme base station or some other other wireless access point<-->computer,
or like this:
    internet<-->modem<--> wired/wireless router<-->computer,
then if the above directions still aren't working for you, we're going to have to dig into likely mismatched configurations between those different devices.
So, did I just make your day or what?