When I plug the HP Deskjet2050j510 printer directly on my PC through USB cable, it is perfect.
But when trying through network, it can not find it.
I'm using the HPLIP Toolbox to search the printer.
I also desactived the firewall.
My internet box is supposed to allow such functionality, it is a Livebox from Orange(France). Here is the documentation, but for Windows, not Ubuntu
My network installation is the following one: 2 PCs connected to the Livebox and the printer connected by USB to the Livebox too.