Mac Forum / General / General / August 2007

There are at least three things you would have to do, maybe more.  I
don't know if you've done these things already since you didn't say.

1) make sure file sharing is turned on for your colleague's machine.

2) using his machine's IP address (which you can find in System
  Preferences -> Network -> Configure -> TCP/IP, put his machine in
  the DMZ for the router at his house.  (Instructions on how to do
  that depend on the particular router, of course, but you should be
  able to figure it out from the router's web page).

3) Try to ftp to his IP address using the WAN IP address of his
  router/cable modem or router/dsl modem or whatever he has.

This still may not work for various reasons, though it works for me.
One reason it could fail is that his ISP could have a firewall
blocking incoming FTP connections.

Not sure about an easy way. If I wanted to do that I might try to set
up a VPN as a first step.

Getting FTP to work is tricky. You need to know whether the client is
doing active or passive FTP and then make sure both the control and
data connections can get through any firewalls. Since the data connection
uses a random high port it is not simple unless you just take down all
firewalls. I wouldn't ever bother trying it. Better to use rsync over ssh
or set up a VPN and then use that.

Ian

There could be many things wrong here.

How are you addressing the ftp connect command to your friend's machine?  
If it's by an IP address like 192.168.x.x, that may be the problem as
that address isn't routable.  You'll need to setup either a static IP
address (rare unless you pay big bucks for it through your ISP) or use a
dynamic IP service:

http://www.no-ip.com/services/managed_dns/free_dynamic_dns.html
http://www.dynip.com/

or

Maybe ftpd isn't running on your friend's machine (enable it in the
System Perferences Sharing panel)

or

Maybe your friend's machine is behind a firewall which prevents inbound
ftp access (check with your friend's network setup -- he'll have to
create a "whole" in his firewall for you)

or

it could be a number of other things.

I think the easiest thing for you is to ftp files to the web space your
ISP offers and have him ftp from that server.  Otherwise, you'll have to
learn a whole lot about how networks work to get this going.  And most
big ISP don't want their customers running a server on their networks.
ftpd running makes your system a file server and unless you know what
you're doing, you may invite all sorts of warez kiddies to store stuff
on your machine.

A word of caution:  You definitely don't want to do it with System
Preferences > Sharing > Personal File Sharing, because it's extremely
insecure unless you are connecting to Mac OS X Server with encryption
enabled. Whatever method you settle on, you'd better make sure it's a
secure one if it's going out over the net!

Get and install HamachiX on both systems.
<http://hamachix.spaceants.net/>
HamachiX establishes a Secure VPN between systems across the
internet and transparently deals with home NAT routers and ISP
DHCP assigned IP addresses.

One Mac uses HamachiX to create a private network and password
   HamachiX -> Networks -> Add Network
(just pick any unique name you like for your private VPN network,
and specify Create on Demand).

The first Mac can then use Network -> Invite to send a connection
file with all the VPN details to the other Mac user.

Or the 2nd Mac can also use Add Network and Create on Demand
specifying the same private network name and password to join the
already created network setup by the first Mac.

Now to connect to connect to the file server on either Mac, use
   HamachiX -> Networks -> Connect using... -> AFP
At this point the dialog boxes will be the normal Apple file
sharing dialog boxes.

This is so trivial to do that you maybe tempted to say D'oh.  But
don't yield to temptation, as you were smart enough to ask a good
question.

                                       Bob Harris