====== Fix cloning eth0 ======


When cloning an Ubuntu VMware virtual machine, eth0 goes missing. Fix the problem by deleting <code>/etc/udev/rule.d/70-persistent-net.rules</code> and rebooting.

I ran into an annoyance trying to clone some Ubuntu LAMP virtual machines that I was using for website development. Every time I cloned the virtual machine, <code>eth0</code> would go missing, and <code>ifconfig</code> would show only the loopback device, lo.

It turns out that when you clone a VMware virtual machine, the cloned virtual machine’s network interface gets a new MAC address (which, of course, it must to work on the same LAN). But Ubuntu, and many other Linux distributions, cache the old MAC address in a configuration file.

In Ubuntu, the file is <code>/etc/udev/rules.d/70-persistent-net.rules</code>. After cloning, it will contain a reference to the old network interface as <code>eth0</code>:

{{ :wiki:70-persistent-net-rules-vi-before.png |}}

The easiest way to fix this problem is to simply delete the file. Ubuntu will regenerate it properly the next time it boots up.

<code> $ sudo rm /etc/udev/rules.d/70-persistent-net.rules </code>

After deleting the file, you need to reboot.
If you can't reboot server please read [[vmware:manually_trigger_creation|]].

After rebooting, <code>ifconfig</code> should show <code>eth0</code> and everything should just work.

If you’re feeling less adventurous, you can rename the file to *.old so that you can restore it if something doesn’t work:

<code> $ sudo mv /etc/udev/rules.d/70-persistent-net.rules /etc/udev/rules.d/70-persistent-net.rules.old </code>

You can also edit the file to remove the old reference to <code>eth0</code>, and rename the new <code>eth1</code> reference to <code>eth0</code>. But deleting the file and rebooting seems more convenient.

The relevant filename is slightly different in other Linux distributions. For example, in Debian, the filename is <code>/etc/udev/rules.d/z25_persistent-net.rules</code>.