On Tue, Aug 21, 2018 at 11:08:10PM +0100, Eric S Fraga wrote: > On Tuesday, 21 Aug 2018 at 16:58, Glenn English wrote: > > On Tue, Aug 21, 2018 at 3:39 PM Eric S Fraga <e.fr...@ucl.ac.uk> wrote: > > > >> Would somebody please point me to the right magical incantation that > >> would allow my desktop computer to have both connections active > >> simultaneously? > > > > I've done that on a couple boxes here -- a laptop (WiFi and an > > Ethernet) and a workstation (2 Ethernets) > > > > On both of them, I wrote a /etc/network/interfaces script to give an > > IP to the Ethernet and start at boot. The others are DHCP and don't > > come on at boot. > > Thanks. I added a few lines to /e/n/i and everything works just fine > now. The actual lines are > > ,---- > | # the USB network for my Gemini > | auto enp0s29u1u1 > | iface enp0s29u1u1 inet static > | address 10.15.19.80 > `---- > > and I simply "sudo ifup enp0s29u1u1" when I need it. > > But I still do not understand why it works automatically on one of the > systems but not the other. One of those mysteries, I guess.
Static configuration is by necessity (basically) custom setup - i.e. requires manual intervention. Automatic means the above /e/n/i lines would look like this instead: # the USB network for my Gemini auto enp0s29u1u1 iface enp0s29u1u1 inet dhcp But of course for network-manager, it would by default use dhcp, and you would not manually configure for DHCP in your /e/n/i file. Always remember you can do an in-foreground one shot DHCP like so: sudo dhclient -d enp0s29u1u1 which has the benefit that you can easily kill it as desired with a CTRL-c, AND you can monitor its output immediately, AND you will see immediately if you got the device/ interface name wrong. What's not to like? Good luck,