You will need to make sure ports 27045, 27046 and 27900 are open. I have put some screenshots from both my old and new routers to give you some idea.
Note due to the forum cropping off some of the images, right click them and open in a new tab / window to see the whole image.




Note due to the forum cropping off some of the images, right click them and open in a new tab / window to see the whole image.