[175523] in North American Network Operators' Group
Re: Linux: concerns over systemd [OT]
daemon@ATHENA.MIT.EDU (Jeffrey Ollie)
Thu Oct 23 02:55:49 2014
X-Original-To: nanog@nanog.org
In-Reply-To: <20FF6E1A-D8A0-4B61-BAE0-3150244565B6@gmail.com>
Date: Thu, 23 Oct 2014 01:55:40 -0500
From: Jeffrey Ollie <jeff@ocjtech.us>
To: George Herbert <george.herbert@gmail.com>
Cc: NANOG <nanog@nanog.org>
Errors-To: nanog-bounces@nanog.org
On Thu, Oct 23, 2014 at 12:28 AM, George Herbert
<george.herbert@gmail.com> wrote:
>
> Ok. As a highly on- list-topic example of why distrust is called for...
>
> Without referring to the systemd source code*, does anyone know what syst=
emd uses to select between networking subsystems (i.e. NetworkManager, the =
new standard as of RHEL 7, vs /etc/ sysconfig/network-scripts/, etc.). Net=
workManager is default but disableable and it magically falls back to netwo=
rk-scripts dir, but the fallback is nearly undocumented and the selection b=
ehavior appears completely undocumented.
systemctl status NetworkManager.service
systemctl status network.service
I don't think that there's anything magic about it, you have one or
the other enabled. Adding NM_CONTROLLED=3Dyes/no to
/etc/sysconfig/network-scripts/ifcfg-* gives you per-interface control
over whether NetworkManager or the network scripts are used for
managing the interface. If neither is enabled you probably end up
with no networking.
> If by some chance you do know this, where did you come by that knowledge?=
Hopefully with URLs.
I have access to systems that run systemd and I tried a couple of
things... Also, I've been managing Red Hat systems for a long time
and have known about this for a while. But a little bit of googling
and I found this:
https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/7/ht=
ml/Networking_Guide/sec-NetworkManager_and_the_Network_Scripts.html
Unless you're running systemd-networkd, this is really distro-specific
stuff as I expect that most distros will want to preserve some
backward compatibility with "legacy" network configuration.
--=20
Jeff Ollie
