I also have D-link router and they suggested using Virtual Servers instead of the Port Forwarding in the admin page
I have set up the name as OpenSprinkler, Public Port as 8888, Protocol as TCP and Schedule as always. In the second line I have the Static IP address for the OS controller, Private Port as 80, Protocol as 6, and no filtering
I have my external IP from the whatsmyip google search
I should be able to go http://externalip:8888 to get to the login for my controller correct?
I have tried taking my phone, disabling wireless, and then pinging my router. I can ping the router using its external IP address and port 80. I get timeouts when pinging port 8888.