I "solved" this problem by deleting the wireless connection and then adding it again.
> On Debian Jessie I have to add the gateway to be able to get internet > over a wireless connection. I do this by the command: "route add default gw > 192.168.0.1 wlan0" > How to make the gateway available automatically on booting like it was > before? > > Extra info: > I managed to connect two computers on a network using SSH. In doing so I > had changed the wireless network connection IPv4 settings from DHCP to > manual to obtain a static IP address. I reverted it after the succesfull > test. I do not recall making any other changes to the network settings. > > Hope someone can help me on this one. Thanks. > > -- > Securely sent with Tutanota. Claim your encrypted mailbox today! > https://tutanota.com