I updated a virtual machine running Ubuntu server 15.04 to the just released new stable 15.10.
There were no apparent problems, but after reboot the machine lost its network connection. lspci
showed the correct card and lsmod
proved that the driver had been loaded.
Hints about editing or removing /etc/udev/rules.d/70-persistent-net.rules
did not succeed (still no network, no new file), the famous /lib/udev/write_net_rules
did not even exist.
I don't have much clue regarding udev and systemd, so it took me some time to find in /sys/class/net that the network interface name changed. It became ens32
, which was renamed from eth0
. After I changed /etc/network/interfaces
network communication was enabled again.
But - why does this happen at all? And if it happens, shouldn't the interfaces file be updated automatically?
Now that I deleted the virtual network card and created another one, eth0
becomes eno16777728
, which is not so, uhm, nice.
Should this behaviour (at least that of the upgrade procedure) be reported as a bug?
Furthermore, is /etc/udev/rules.d/70-persistent-net.rules
obsolete now? And (although only partly related) what about /etc/udev/rules.d/70-persistent-cd.rules
?)
Edit - additional question (after accepted answer)
The dependency of /etc/network/interfaces
from the actual interface name bothered me. I tried a new installation of *ubuntu in another virtual machine. To my surprise, /etc/network/interfaces
contained a reference to the loopback device only. However, with my original VM this change prevented the network to come up. So what else do I need to change?
Edit
Well, from another test I found that a new Ubuntu Server has the network interface card in /etc/network/interfaces
, while XUbuntu has not. Maybe it is using network-manager
or something else.