Centos 7 the journey form NetworkManager to self managed network configuration files

Long time ago that i wrote something. I think it’s time to start with a small one…

While I create a manual installation for Centos 7, i was borrowed by follow message after
disabled the NetworkManager:
(systemctl stop NetworkManager; systemctl disable NetworkManager; systemctl mask NetworkManager)

systemctl restart network … BOOOM (-;

network.service – LSB: Bring up/down networking
Loaded: loaded (/etc/rc.d/init.d/network; bad; vendor preset: disabled)
Active: failed (Result: exit-code) since Di 2017-03-07 19:01:15 CET; 7s ago
Docs: man:systemd-sysv-generator(8)
Process: 3469 ExecStart=/etc/rc.d/init.d/network start (code=exited, status=6)

I wasn’t that stupid, created the file with nmtui. In fact: No mistakes! But the failure
came around from ipv6, what i disabled in the configuration.

Search for a file like “/etc/sysconfig/network”. “touch” it or create empty one.

echo “# Created by anaconda” > /etc/sysconfig/network

your done. Now “systemctl start/stop/restart network “work and the adapter is up on boot.

There is one little thing about loopback device, which is not present NetworkManager:

“ip r”

default via dev enp2s0 dev enp2s0 scope link metric 1002 dev enp2s0 proto kernel scope link src 172.16.200

After read up some forums who tell you “Prevent the kernel from load ipv6”. In Centos 7 the ipv6 module is builtin. 🙂
By the way the backloop ip is ipv 4.

After I add to the ifcfg- configuration file:


Everything looks clean.

“ip r”
default via dev enp2s0 dev enp2s0 proto kernel scope link src

We can still mix ipv4 and ipv6 with another card.

Now everything works like it should;- how simple it can be……

PS: You really know what you install when you “click” inside a gui? 🙂 Me not.

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