4 Replies Latest reply: Feb 19, 2013 7:10 PM by BobHarris
Don Price Level 1 (125 points)

For some reason, I cannot get Screen Sharing to work continuously. I could not get it to work at all (even though I veried the settings were correct), and after reading some posts here, I rebooted my MacBook Pro and voila! it worked - at least on my home network. However, once I get to work, I can no longer connect.


Any ideas?

MacBook Air, OS X Mountain Lion
  • BobHarris Level 6 (17,634 points)

    And how are you trying to connect with your home Mac from work?


    Are you using Apple's iCloud Back-to-My-Mac (BTMM) feature?  It should handle getting through home routers?


    Does you work have a Firewall and proxy servers in place?  They are going to block any attempt at accessing the outside world except via corporate approved networking channels, which frequently do not include Screen Sharing.  If this is the case, I might suggest TeamViewer.com as it has an option for setting a Proxy and if the company has not disabled accessing the TeamViewer.com URL, it might work.


    If no corporate firewall and proxy server, and you are not using BTMM, then do you have a home router?  Did you setup port forwarding for port 5900 from the internet to your home Mac?  <http://portforwarding.com>


    What address are you trying to connect with?  I you have home router you need to use the IP address assigned by your ISP to your home router.  If you do a Google search for "what is my ip address", Google will tell you your Public IP address.  You need this for your home router.


    BTMM and TeamViewer.com avoid the need to know your Public IP, and port forwarding.  Corporate firewalls are a beast of their own, and have to be handled on a case by case basis.  Some will let you get through, some will not.


    If you find you are going to be using the Public IP address of your home router, then you want to get a free dynamic DNS name for you home Mac from No-IP.com or DynDNS.org and then run the dynamic DNS updating utility provided by the dynamic DNS service on your home Mac to keep the dynamic DNS name updated each time your IPS changes your public IP address.

  • Don Price Level 1 (125 points)

    Wow - fast reply with lots of info!


    First, I am using an Airport Extreme router behind a firewall; however, even after disabling the firewall, my problem still occurs. I am using BTMM - and, to my knowledge, I have it set correctly.


    I was selecting my home Mac from the Finder, but if there is a more reliable way, I am happy to do that.


    Please let me know what other info you might need to help diagnose my problem - and thanks!



  • BobHarris Level 6 (17,634 points)

    I was selecting my home Mac from the Finder, but if there is a more reliable way, I am happy to do that.

    If your home Mac was appearing in your Finder sidebar while you were at work, then this indicates iCloud and Back-to-My-Mac is at least communicating.  Unless this is just left over from when you were at home.


    You need to detail the networking gear at each end.


    Is there a separate router from the ISP in front of the Airport Extreme.  Going through 2 routers can make it difficult for BTMM to make a connection.


    And the question applies to both the home Mac and the work Mac.  What is the exact network gear at both ends as either side could be causing connection issues.


    As an experiment, you could try TeamViewer.com, and if it also fails, then there is a networking configuration issue.  If TeamViewer.com works, then you have an alternate method you can use until you get BTMM working.

  • BobHarris Level 6 (17,634 points)

    Previous post was delayed, so I didn't think it got posted, so I tried again.  But now I see it did show up, so I edited this down to nothing :-)


    Message was edited by: BobHarris