Super User is a question and answer site for computer enthusiasts and power users. It's 100% free, no registration required.

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

After I cloned a VirtualBox VM image, either original nor cloned Debian 6 (squeeze) image have networking works anymore.

I've read A TON of articles online describing modifying the /etc/udev/rules.d/70-persistent-net.rules and /etc/udev/rules.d/75-persistent-net-generator.rules files but none of those "fixes" worked for me.

(Apparently this is a "feature" of UDEV that causes all kinds of problems if you are using Debian/Ubuntu in a virtualized environment for development and want to clone images because it changes your MAC address of your virtual NIC).

Can someone please described exactly what I need to do in order to have networking working again in my VM debian images. Thanks

Note: networking stopped in BOTH (all) debian virtual images now. Essentially, 1 how do I fix my MAC address since I don't even know what MAC address should now be used, [2] how do I prevent this from happening in the future when I clone VM images?

UPDATE: My problem was filed as a bug with both VirtualBox and VMWare but both companies closed the tickets stating this is a "feature" of Debian. Some people suggests ways to fix the problem but none have worked.

share|improve this question
Happens when cloning fedora machines too as of Virtualbox 4.2.8. I thought updating Virtualbox would fix the dns but it doesn't. I have yet to try @raydos answer because doing the same operation on fedora is different. – Trevor Boyd Smith Mar 4 '13 at 14:41
The MAC address of your virtual nettwork cards can be found and changed in the settings of your virtual machine. For virtualbox, shut down the guest, right click the guest and go into the network settings. – Lennart Rolland Jan 22 '14 at 10:59

I don't know if you are still tracking this problem but, I have encountered this problem too and the solution that works consistently for me when I do clone a Debian guest is as follows:

  1. Prior to cloning, shutdown the VM to be cloned.
  2. Clone the VM (make sure you select "Reinitialize the MAC address of all network cards")
  3. Boot the clone VM and edit the /etc/udev/rules.d/70-persistent-net.rules as root. Remove all references to interfaces. These will be rebuild automatically the next time you boot.
share|improve this answer
Excellent, fixed my problem. – andynormancx May 23 '14 at 10:42
With Debian Jessie the directory /etc/udev/rules.d is empty. – Ortomala Lokni Feb 5 at 20:58

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.