Remote share screen set up

Question

I have an ADSL connection through a KPN Experia Box (router). I have connected my Airport Express to this router with an ethernet Cable. My MacBook an iMac run perfectly on the Airport Express. I see both computers and I can share the screens.
Now I would like to be able to do the same when I am not home, so from another place "take over" the screen of my iMac at home.
Can someone help me to set this up? I suppose that I first need to get acces to my router and from there to the Airport Express...? I am not very good in this networking business, please help...

Answer 1

First of all make sure your airport express is setup as a bridge and not set to share your public ip address.
Then the best way to do screen sharing is through SSH as SSH is very secure.
So login to your router's WebUI. This is done by putting its IP address into your browser.
eg http://192.168.2.1
Then check what dhcp pool your router is using. Then assign the mac you will designate as your server a static ip address that is outside the range of ip's the dhcp pool is using.
Then setup a port forwarding rule (NAT) to forward tcp port 22 to the ip of your mac.
Then in your macs sharing preferences turn on remote login and screen sharing.
Then you would need a dynamic domain address get one from http://dyndns.com
then setup a dyndns client on your mac (your router may have one so check that first)
so if you got dyndns domain name such as myfunkserver.thru-here.net
when you are away from home open your terminal and use the following login
ssh -L 5901:localhost:5900 [email protected]
once that connection is established open
/System/Libary/CoreServices/Screen Sharing.app
and use a host address of localhost:5901