[libvirt-users] Problem with bridged network configuration

[Laine Stump]

On 11/12/2013 06:52 PM, Bob Doolittle wrote:
> For the record - I figured this out so am sharing the result for
> posterity:
>
> The issue was that I didn't follow the instructions literally. Since,
> once booted, my primary NIC name was "em1" I assumed I had to create
> an initscript called ifcfg-em1 rather than ifcfg-eth0 as described in
> the doc.


But you assumed correctly.


>
> Once I renamed that script to ifcfg-eth0 (and changed the DEVICE value
> in the file to match), all is well. It does indeed appear to be a
> timing issue due to the "Predictable Network Interface Names" feature
> and when its NIC name musical chairs dance begins.


If there is a timing problem, then that is a bug. In udev? systemd?
initscripts? I'm not sure...

Keep in mind, though, that the name of the ifcfg file is definitely
insignificant, and it's possible that the DEVICE and NAME parameters in
the ifcfg file may be ignored at times, as long as there is an HWADDR
and/or uuid to key from.


>
> I have had more problems due to that one feature than anything else in
> recent memory. It is a misnomer if ever there was one. Even the docs
> related to it are incorrect (for Fedora 19, creating the symlink
> described at
> http://www.freedesktop.org/wiki/Software/systemd/PredictableNetworkInterfaceNames/
> doesn't have the expected result of disabling the feature).


Are you sure that F19 has that form of netdev naming in the first place?
The non-integrated netdevs on my F19 system have names based on their
slot, e.g. "p4p2", not the type of names specified in the web page you
reference above (e.g. "enp2s0"). Even my F20 system seems a bit up in
the air - what had been called "wlan0" in F17 is now called "wlp3s0"
(which seems like one of the new names), but an ExpressCard ethernet
plugged into the system is still classified as "p3p1".