How can I connect to my home computer from work?
I have a couple of computers at home, running Windows XP Home and XP Pro.
They are connected to the internet using a broadband router. I'd like to connect to them from my place of work. How do I do that?
Well, it may be possible, but there are several barriers in your way. It could get
complicated, but we'll look at each of the barriers in turn, and consider ways to overcome them, if possible.
First, I'm going to assume that you want to connect using Remote Desktop. Using
that, when you finally do connect, you'll have access to the remote computer
almost as if you were sitting in front of it. The bad news here is that Remote
Desktop is a feature of Windows XP Pro, and is not present in XP Home. You'll
only be able to access your XP Pro machines using Remote Desktop.
Our first barrier is your place of work. Depending on how they are connected
to the internet, you simply may not be able to connect out. Larger corporations
often restrict what protocols are allowed to access the internet. Quite often they
restrict access to web surfing and email. If that's the case where you work, there's
little recourse, other than pleading with your IT department to allow the Remote
Desktop protocol (on port 3389) to reach the internet.
The next barrier, or at least point of confusion, is your IP address. The easiest
scenario is if you have a static IP address at home. That way you'll always know
what IP address to connect to. In fact, if you have a static IP, you can even
register and assign a domain to it, so that you can access your home network
by name - something like myhome.mydomain.com - rather than IP address.
If you have a dynamic IP address, you can still get to your network. You simply
need to know what the current IP address is. There are several approaches,
however none of them are really elegant. For example, you can call home and ask
someone to visit a site such asPlot IP, which will display your IP, and then have
them read it to you over the phone. If you have access to a web server's access
logs, you can have your computer at home visit a specific web page periodically
and retrieve the IP address from the logs. And finally there are tools that you can
use to map a domain name - like myhome.mydomain.com - to a dynamic IP.
These tools do require that you install software on your computer to detect IP
address changes, and when a change occurs, it may take up to 48 hours for the
DNS changes to make their way across the internet.
The good news about a dynamic IP is that if your router stays connected
continuously, the IP address is actually not likely to change often.
The next barrier is your router. A router acts as a firewall, and prevents most
connections coming in from the internet. Most people only connect out, to surf
the web, download files or read email, so that's not a problem for them. But
connecting from a remote location to your home is a connection coming in
from the outside. The router needs to be configured to forward port 3389 (the
Remote Desktop Protocol port) to the computer you want to connect to.
Unfortunately, exactly how that's done will vary depending on kind of router
you have - you'll have to check the documentation.
Note that I said you need to configure it to forward to the computer you want
to connect to. You can access only one of your computers directly through your
router this way. (There are techniques where you can specify that Remote Desktop
listen on ports other than 3389. Then by using a different such port for each
computer, and forwarding each through the router to the appropriate computer,
you can connect directly to each. That's beyond the scope of this article, and more
complex than most folks will want to deal with.)
My approach, for what it's worth, is to allow external remote access to only one
machine on my network. Once connected to that machine I can, if needed, use
Remote Desktop on it to connect to any other machine on my network. It can be
a little confusing from a UI perspective, knowing which of the three machines
connected in sequence my keystrokes are actually going to, but in practice I don't
do it often.
Our final barrier is your IP address on your LAN. Your IP address on the
internet, whether static or dynamic, is assigned by your ISP and really identifies
only one device: your router. Within your local network, the router then typically
assigns local IP addresses to all of your computers. The router then handles making
sure that all the data traveling between the computers on your local network and the
internet all go to the right computers.
Those local IP addresses never leave your network - the internet sees only your
router's IP address. So when you configure your router to forward port 3389 to a
computer, you need to select one of your local computers, and configure its IP
address as the destination for Remote Desktop. Then, when the router receives a
Remote Desktop request from the internet, it forwards that request to the computer
whose IP address you configured.
The "problem" is that your local network is, more than likely, using dynamic IP
addresses. That means that the IP addresses that are assigned to each computer
could change over time. If you leave your computers on all the time, the addresses
won't change, and you're probably OK configuring the router with the current IP
address of the computer you want to access remotely. If it ever changes, you'll
need to update your router's port forwarding configuration for port 3389.
If that's unacceptable or inconvenient, the only real solution is to configure one of
your computers to have a static IP address, and then configure the router to forward
to that one as the Remote Desktop target. Depending on your router it can be as
easy as:
(normally 192.168.1.1 is reserved for the router itself).
In many cases that's enough. In cases where other machines on your network
cannot "see" this one machine, it may be necessary to add an entry to the "hosts"
file on all the other machines that defines the static IP address for this one machine:
There are other solutions, but I've not tried any of them myself so I'm not qualified to comment on their suitability or their ease of setup:
support built in.
Perhaps some readers will chime in with their experiences with those, or other,
solutions.
Note: "You'll only be able to access your XP Pro machines using Remote Desktop. not home basic" |
