One more point if you have more than 1 computer on your network.

You need to set your configuration so the it gets the SAME
internal IP so port forwarding works.
Depending on your routers DHCP server's features. You may be able to 'reserve' a preset internal (192.168...) address by entering the MAC of your machine( eg. a1:b2:c3:f4:56:08) This features allows a laptop to still be fully portable (DHCP), but have a 'static' like address at it's home base.
Assign a Static IP (be sure to be above the DHCP assignment range, so someone else does NOT get
your address).