The following Guest Post is from Joey Heape, Director of Media & Tech for the South Carolina Bar:
At South Carolina Bar, I normally work in a Windows environment and use Remote Desktop that comes as a part of Windows XP Pro to access workstations, administer our local servers and our web server. While I use a PC at the office I use a MacBook Pro or a Mac Pro when I’m at home or on the road. So how do I do this? Well, I use Microsoft’s Remote Desktop Connection for the Mac. Microsoft has had this product for a number of years and it works quite well. It’s a free download and works great if you are using a Mac to control a PC.
South Carolina Bar is mostly a Windows environment. However, we have eight Mac workstations and three Mac laptops in our environment too. Those that work from home using Macs have to be able to access their Mac workstations with a Mac from home. There are many companies that offer remote control products like GoToMyPC , MobileMe or some subscription based model where you access your destination computer through a third-party. While these are easy to do they cost you a monthly subscription.
Enter Apple Remote Desktop. Since I’m the system administrator at South Carolina Bar, we have purchased Apple’s Remote Desktop product to manage the Macs on our network. We can update software and do many administrative tasks with this program. But did you know there is a scaled down version of Apple Remote Desktop that comes with Mac OS X? It’s called Screen Sharing.
Screen Sharing allows you to control a Mac running OS X with another Mac running OS X much like Remote Desktop does in the Windows world. Screen Sharing is part of iChat but can be accessed independently as well. The Screen Sharing application can be found by using Finder. It resides under /system/library/coreservices. Once you have found it you can drag it to the dock. Some of the following is excerpted from MacFixIt.com (why reinvent the wheel?)
There are a few things you will need to do to your computer before Screen Sharing will work.
Before you attempt a screen sharing connection, should do the following on the destination computer (the one you want to control):
- Open the Sharing System Preferences pane. At the top of the Services list is Screen Sharing. Select it and turn it On. Note: if Remote Management is checked you will need to uncheck it in order to enable Screen Sharing. If your IT folks have enabled this consult them before you uncheck it.
- For the moment, where it says "Allow access for:", select "All users." This makes connections easier to accomplish. However, leaving it at this setting is a security risk, so you might want to change this later. I usually create another user called ARDUSER (Apple Remote Desktop user) and apply privileges accordingly.
- Click the Computer Settings button. From the sheet that drops down, make sure the both boxes are unchecked. If you use another VNC program like Chicken of the VNC you will need to leave the lower box checked.
- The destination computer is now ready to accept a connection.
- You will need to know the IP address of the destination Mac before you will be able to connect to it. If both computers are on the same network open Screen Sharing on the Mac you want to use to control the destination Mac and type in the IP address of the destination Mac. Next click connect. You should be able to see and control the destination Mac just like you sitting there.
This is pretty easy and straightforward when both Macs are on the same network but what about when they are across the internet? Screen Sharing has a set of virtual "ports" which isolate network traffic for the Screen Sharing protocol. This means firewalls on the local computer, as well as any routers or hardware firewalls must also be set up to pass or forward traffic on the respective ports. Most home wireless routers have a port-forwarding feature in them that allows you to take incoming connections on those ports and forward them to a destination computer in your local network.
The connector on your router that is connected to your DSL or cable modem is the internet side or WAN. It is assigned an IP address by your ISP and you cannot change that. On your local or home network usually your router assigns the IP addresses to all of the local machines. In the router setup, and all vary by manufacturer, you will need to route incoming traffic on ports TCP 5900-5902 to the IP address of the destination Mac. This will force any incoming Screen Sharing connection requests to the destination Mac.
Once you have configured your router you will need to find out the IP address. The router internet IP address is the IP address you will use to connect to the destination Mac while outside of the local network. If you are on a corporate network, check with your IT department on how to connect to your computer while away from the office. They should be able to help you with this.
Security is another concern when connecting to your local computer from the internet. I don’t have enough space to go in to security but I will leave you with some resources. This article and this article cover what I did in more detail. It actually goes into security.
Screen Sharing is one of the unsung heroes of OS X and has certainly made our life here easier.