New subject: eth0 again - the end

Sunday, 20 July 2014

I have to install Matlab on a Fedora 20 machine and I need to rename the 
network device to eth0, or else Matlab won't install. This is a known issue:

http://www.mathworks.com/matlabcentral/answers/100235-why-can-t-i-activat...

So, to revert to eth0, I follow these instructions:

http://www.freedesktop.org/wiki/Software/systemd/PredictableNetworkInterf...

It says I have 4 options. I did ALL of them and still 

[root@phoenix ~]# /sbin/ifconfig
em1: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
        inet 192.168.1.40  netmask 255.255.255.0  broadcast 192.168.1.255
        inet6 fe80::20c:f1ff:febc:29fe  prefixlen 64  scopeid 0x20<link>
        ether 00:0c:f1:bc:29:fe  txqueuelen 1000  (Ethernet)
        RX packets 713  bytes 306565 (299.3 KiB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 979  bytes 131054 (127.9 KiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

etc.

Specifically, I have masked /usr/lib/udev/rules.d/80-net-name-slot.rules 
by creating a link /etc/udev/rules.d/80-net-name-slot.rules -> /dev/null.

[root@phoenix ~]# ls -l /etc/udev/rules.d/
total 8
-rw-r--r--. 1 root root 151 Jul  6 20:31 70-persistent-net.rules
lrwxrwxrwx. 1 root root   9 Jul 20 10:36 80-net-name-slot.rules -> /dev/null
-rw-r--r--. 1 root root 352 Apr  3 04:36 98-kexec.rules

I also have an /etc/udev/rules.d/70-persistent-net.rules: 

[root@phoenix ~]# cat /etc/udev/rules.d/70-persistent-net.rules 
SUBSYSTEM=="net", ACTION=="add", DRIVERS=="?*",
ATTR{address}=="00:0c:f1:bc:29:fe", ATTR{dev_id}=="0x0",
ATTR{type}=="1", KERNEL=="eth*", NAME="eth0"

I also passed net.ifnames=0 to the kernel upon boot:

[root@phoenix ~]# dmesg | grep ifnames
[    0.000000] Kernel command line: BOOT_IMAGE=/vmlinuz-3.15.6-200.fc20.i686+PAE
root=UUID=aa696c85-f1d4-4bf3-9a93-b011ec8e9a6a ro vconsole.font=latarcyrheb-sun16 rhgb
quiet net.ifnames=0 LANG=en_US.UTF-8

Someone must have figured this out. Can anybody please help me solve this?

Also, NetworkManager might have something to do with this, because if I 
right-click the NW applet -> Edit Connections, I do have a connection named 
eth0, but if I try to edit that, the device MAC address is 

00:0c:f1:bc:29:fe (em1)

So NW somehow likes em1, despite all my efforts. If I stop and disable NW, 
then the network does not even start upon boot, as it should. How do I tell 
NW to leave my network alone and still have the network start upon boot?

Thanks!