no network after installing ubuntu 16.10

[John G Heim]

On 02/07/2017 05:20 PM, Ian Kelling wrote:
> On Fri, Jan 20, 2017, at 09:10 AM, John G Heim wrote:
>> Thisisn't directly an FAI problem but I don't know where else to ask. I
>> am trying to upgrade a working FAI setup for Ubuntu 16.04 to install
>> 16.10. After rebooting, my machines have no network connection. The
>> NetworkManager package is installed but it isn't managing the nic. If I
>> type "dhclient eno1", it gets a dhcp lease and then everything is
>> normal. So what ever is creating eno1 is working, it's just that
>> NetworkManager doesn't think it should be managing it.
>>
>> I have a Ubuntu 16.10 system that I installed from the Ubuntu ISO. I've
>> painstakely compared every thing in /etc/network/, /etc/NetworkManager/,
>> and /etc/systemd/ and can't find any significant differences.
>>
>> Any ideas at all?
>>
>>
>>
>> --
>> --
>> John G. Heim; jheim at math.wisc.edu; sip://jheim@sip.linphone.org
>
> The example fai config does not have NetworkManager manage the
> non-wifi nics like eno1. Can you give us some details of your config?
> For example, what is in /etc/network/interfaces?
>



I messed around with the contents of /etc/network/interfaces quite a 
bit. I did this both by editing the file by hand after the install and 
by editing the 30-interface scriptthat is part of the fai package. 
There used to be a bug in NetworkManager such that it would fail if 
there were comments in the file, /etc/network/interfaces. It has to 
parse that file to know if an interface is supposed to be managed by 
NetworkManager. If an interface is not in /etc/network/interfaces, 
NetworkManager is supposed to manage it, right? But it doesn't work.

So here is one example of the /etc/network/interfaces file:

auto lo
iface lo inet loopback



[Note that I even took the comments out where it says it was generated 
by fai.]