I'm trying to connect my desktop and laptop using an ethernet connection. I usually configure network from the command line but this time I decided to give Network Manager a try, so I went to Network Connections, and selected manual IP configuration.

At first I left the default gateway field blank, since I don't need a default gateway. Turned out network manager doesn't let me save the connection unless I enter that field, but entering a phony gateway messes up with my Internet connection. Anyway to do this setup?