SocketTimeoutException: Read timed out - But it works with PhpStorm

I try to connect to my remote host from NetBeans.

Host Name: blizz.powered-by-rackspeed.de

Port: 21

I am using NetBeans 8.2 (Build: 201609300101)

It works perfectly fine in PhpStorm with Port 21 though, so it must be a NetBeans Bug.