Re: on manual configuration / respecting user made changes

[Xen <list xenhideout nl>]

Dan Williams schreef op 05-04-16 19:47:
> On Tue, 2016-04-05 at 10:53 +0200, Xen wrote:
> > Question:
> >
> > Currently when NM manages a link/device (say eth0) any attempt to
> > manually configure it (using e.g. ifconfig) will quickly result in
> > this
> > action being undone by NM.
>
> That should not be the case with NM 1.0 and later.  These versions make
> huge efforts to preserve additional IP configuration you add to the
> interface, both addresses and routes.

Right. It is in (K)ubuntu 16.04, with NM 1.0.4, the interface/device had
default configuration which is DHCP, I had been using DHCP for a while
but needed to test something.

With the remote DHCP server at that point not working, I needed manual
configuration quickly, so I did "ifconfig enp0s25 192.168.1.5" followed
by "ifup enp0s25".

I opened SSH to the host, but my connection got lost within about 20
seconds and my device ended up being deconfigured (or reconfigured for
dhcp, which didn't work).


> Anything you add over-and-above what NM does (even if NM does nothing)
> should be preserved.  I just tested with NM 1.0.10 and an ethernet
> interface that NM showed as "disconnected" (because NM had not
> activated a connection on it).  Simply running "ip addr add 1.2.3.4/24
> dev enp0s25" caused NM to move the device to "connected" state and
> report the added IP address.  NM reads the added configuration and
> won't change it.

That's good to hear. I have always been bugged by this. For example,
even on Debian 7 the behaviour was the same, and I had to take NM off of
the interface to be able to do any manual configuration.


> > Should there be any sense of not interfering with manual
> > configuration?
>
> Yes, NM spends a lot of effort to do this.

Right.


> > I mean in a general sense what you see happening is this:
> >
> > 1. If some device is configured over DHCP in NM, but DHCP might be
> > failing and there is nothing configured
> > 2. Manual configuration of the interface to a certain IP will work
> > for
> > about 20 seconds, after which NM will deconfigure the device.
>
> What NM version are you using?  This works for me on NM 1.0 as
> described above.

Currently 1.0.4-0ubuntu10 (package name).

Nmcli version is 1.0.4.