@sanyaade
So have you decided how you're going to configure the IP Address for the device? Manual or DHCP?
The advised approach would be let DHCP assign the IP and set the "Always use this IP address" to 'Yes' found in the >Advanced Settings >My Network >My devices .
I would also recommend when setting up the port forward rule to use the "device name" rather than IP address, the logic behind this is the hostname should not change, where as a DHCP IP might.
Please note; do not quote the previous post in full as this is against forum rules, it is really not necessary and keeps the thread easier to read.
