Comment 0 for bug 1608646

lsb_release -rd:
Description: Ubuntu 16.04.1 LTS
Release: 16.04

Network Settings package version in Software Center:
15.04.0+16.04.20160705-0ubuntu1

Prior to upgrading to 16.04 LTS I was running 14.04 LTS. Using the "Edit Connections..." menu option I had created a custom Ethernet connection that had some custom routes added. These routes are required for me to connect to certain resources on a local network while using Wifi for basic internet. (Physical network locked down, no Internet access available)

I've attached a screenshot showing the routes. These routes were working great in 14.04 (And prior releases of Ubuntu).

However, upon upgrading to 16.04, I noticed this connection would no longer "connect". It would just silently fail. I noticed that if I deleted my custom routes, it would work, but I need those in order to connect to my required network services.

When I try to connect with the routes in place, the connection silently fails in the NetworkManager UI (I get no error message in the UI) but I took a look at syslog and found these:

Aug 1 08:15:19 jeremy-ThinkPad-X1-Carbon-4th NetworkManager[2868]: <error> [1470057319.7268] platform-linux: do-add-ip4-route[2: 10.104.0.0/16 0]: failure 101 (Network is unreachable)
Aug 1 08:15:19 jeremy-ThinkPad-X1-Carbon-4th NetworkManager[2868]: <error> [1470057319.7271] platform-linux: do-add-ip4-route[2: 10.105.0.0/16 0]: failure 101 (Network is unreachable)
Aug 1 08:15:19 jeremy-ThinkPad-X1-Carbon-4th NetworkManager[2868]: <error> [1470057319.7272] platform-linux: do-add-ip4-route[2: 10.51.35.0/24 0]: failure 101 (Network is unreachable)
Aug 1 08:15:19 jeremy-ThinkPad-X1-Carbon-4th NetworkManager[2868]: <error> [1470057319.7273] platform-linux: do-add-ip4-route[2: 10.140.76.0/24 0]: failure 101 (Network is unreachable)
Aug 1 08:15:19 jeremy-ThinkPad-X1-Carbon-4th NetworkManager[2868]: <info> [1470057319.7281] device (enp0s31f6): state change: ip-config -> failed (reason 'config-failed') [70 120 4]
Aug 1 08:15:19 jeremy-ThinkPad-X1-Carbon-4th NetworkManager[2868]: <warn> [1470057319.7289] device (enp0s31f6): Activation: failed for connection 'Windstream'
Aug 1 08:15:19 jeremy-ThinkPad-X1-Carbon-4th NetworkManager[2868]: <info> [1470057319.7309] device (enp0s31f6): state change: failed -> disconnected (reason 'none') [120 30 0]

Now, if I remove the custom routes from the UI, then I can connect. I them manually add the routes using the "ip" command:

sudo /sbin/ip route add 10.104.0.0/16 dev enp0s31f6
sudo /sbin/ip route add 10.105.0.0/16 dev enp0s31f6
sudo /sbin/ip route add 10.51.35.0/24 dev enp0s31f6
sudo /sbin/ip route add 10.140.76.0/24 dev enp0s31f6

This is able to add the routes successfully. So there has to be some problem in the new implementation of NetworkManager in 16.04, because these routes worked in 14.04 and they still work in 16.04 if I just manually add them from the command line.

For now I can work around this issue by manually adding these routes from the command line every time I connect.