[Mageia-dev] network interface renaming not working anymore

Thu Aug 16 22:55:19 CEST 2012

On Thu, 16 Aug 2012, Colin Guthrie wrote:
+
+> 'Twas brillig, and Christiaan Welvaart at 16/08/12 20:30 did gyre and
+> gimble:
+>> hi,
+>>
+>> When I finally rebooted a cauldron system that acts as a router, it
+>> turned out the network interfaces eth0 and eth1 were switched, exposing
+>> "internal" services to the outside world and leaving me without internet
+>> access. Syslog contains:
+>> Aug 15 22:48:29 zem systemd-udevd[404]: error changing net interface
+>> name eth0 to eth1: File exists
+>> Aug 15 22:48:29 zem systemd-udevd[404]: error changing net interface
+>> name eth1 to eth0: File exists
+>>
+>> Of course this has worked for years, so it breaking is not something
+>> anyone would expect. It also seems to be unneeded. After some looking
+>> around I could (temporarily) fix it quite easily by adding:
+>>         ifrename -i eth0 -n rename0
+>>         ifrename -i eth1 -n rename1
+>>         ifrename -i rename0
+>>         ifrename -i rename1
+>> to /etc/init.d/network and describing the mapping in /etc/iftab . So now
+>> I have two questions:
+>> - Has anyone else seen this?
+>> - What change is causing this: kernel, udev/systemd, or something else?
+>>
+>> The network devices use the same driver so there is no other way to
+>> distinguish them than by MAC address or PCI ID.
+>
+> Yeah this is no longer supported upstream as it was apparently very
+> hacky. Last time I asked Kay about it, there was something else to
+> replace it but I've not followed up what that is recently. I'll ask him
+> again next time we're chatting.
+
+So it's udev (I tried to install an old udev but that didn't work). Commit 
+looks to be:
+http://cgit.freedesktop.org/systemd/systemd/commit/src/udev?id=97595710b77aa162ca5e20da57d0a1ed7355eaad
+
+Waiting 90s hoping the interface name becomes available is no fun of 
+course but in fact this works fine when the user configured it properly: 
+it did exactly what I now use as workaround only without global control. 
+So we could simply revert it but I wonder why this change was considered 
+necessary. So far I have not found any discussion about it.
+
+
+     Christiaan
+