2

I am running Ubuntu 18.04 and trying to get a VPN (L2TP/IPSec) connection to my company. The necessary tools are already installed and I have a profile with the correct access data.

However, if I try to activate the VPN with 

nmcli c up VPN

it quits with the following error:

Error: Connection activation failed: Could not find source connection.

If I do a

nmcli device status

I get:

DEVICE      TYPE      STATE            CONNECTION 
br0         bridge    connected        br0        
virbr0      bridge    connected        virbr0     
eno1        ethernet  connected        eno1       
lo          loopback  not managed      --         
virbr0-nic  tun       not managed      --

EDIT: Here on StackExchange, there is similar issue, with two possible solutions. Both don't work for me. Let me explain:

The 1st solution suggests to set 127.0.0.1 as default route. The only way for me to do so, is to set the default route of br0. But then I loose the IPv4 connection until the next restart. Changing the default route back, does not get the connection back online.

The 2nd solution suggests to setup a netplan config. If I do so, I overcome the Could not find source connection.-Error, but I loose complete network access as well (until next reboot).

So these are no working solutions for me. So I hope someone is able to help me.

Thanks.

EDIT 2: So apparently, I missunderstood the 1st provided solution - the default route.

ip r gives me the following output:

default via 10.1.10.1 dev br0 
10.1.0.0/16 dev br0 proto kernel scope link src 10.1.20.25 
169.254.0.0/16 dev br0 scope link metric 1000 
192.168.122.0/24 dev virbr0 proto kernel scope link src 192.168.122.1 linkdown

If I understand this correctly, br0 is the default route!?

netstat -rn gives me the following output:

Kernel-IP-Routentabelle
Ziel            Router          Genmask         Flags   MSS Fenster irtt Iface
0.0.0.0         10.1.10.1       0.0.0.0         UG        0 0          0 br0
10.1.0.0        0.0.0.0         255.255.0.0     U         0 0          0 br0
169.254.0.0     0.0.0.0         255.255.0.0     U         0 0          0 br0
192.168.122.0   0.0.0.0         255.255.255.0   U         0 0          0 virbr0

And my etc/network/interfaces looks like this:

# interfaces(5) file used by ifup(8) and ifdown(8)
auto lo
iface lo inet loopback

auto br0
iface br0 inet dhcp
bridge_ports eno1
bridge_stp off
bridge_maxwait 0
bridge_fd 0

So right now I am not really sure what to do. As of my understanding the default route is set and 

[ifupdown]
managed=true

is set. So, what else could I do? I could try to get rid of that bridge, but I don't know if that would help.

Thanks for any advice.

pixelbash
  • 39
  • 1
  • 5
  • 1
    Does this answer your question? [NetworkManager fails with "Could not find source connection"](https://unix.stackexchange.com/questions/438224/networkmanager-fails-with-could-not-find-source-connection) – roaima Mar 16 '20 at 16:11
  • Well, the 2nd answer helps me to overcome the `Could not find source connection.` issue. But strangely I loose the complete network connection if I do so and I have to restart my machine to get it back. So that's not really a solution. :-/ – pixelbash Mar 16 '20 at 16:39
  • Ok, I just added what you suggested :-) – pixelbash Mar 16 '20 at 23:20
  • It doesn't suggest setting the default route to 127.0.0.1 is the solution. It says that nm must be in control of the default route. And that if you don't have one you can set it to the otherwise useless 127.0.0.1 – roaima Mar 16 '20 at 23:47
  • @roaima, I think you need to help me a bit with this one. I did another edit in the main question above. – pixelbash Mar 17 '20 at 08:19

1 Answers1

1

Ok, so I got it working now.

What helped was: Getting rid of br0. I had to remove it manually in /etc/network/interfaces.

I thought I need this for my kvm-machine, but it turns out: It was not necessary.

My /etc/network/interfaces looks like this now:

# interfaces(5) file used by ifup(8) and ifdown(8)
auto lo eno1
iface lo inet loopback

iface eno1 inet dhcp
pixelbash
  • 39
  • 1
  • 5