What is changing the network interfaces (/etc/network/interfaces)?

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I installed Ubuntu 12.04 to virtual machine. I have edited /etc/network/interfaces like this:

auto lo
iface lo inet loopback
auto eth0
iface eth0 inet dhcp

Then I created a livecd.iso using relinux. Network interfaces is changing after boot from DVD (livecd.iso).

/etc/network/interfaces after boot from DVD:

auto lo
iface lo inet loopback
auto eth0
iface eth0 inet dhcp
auto wlan0
iface wlan0 inet dhcp
auto eth1
iface eth1 inet dhcp
auto wlan1
iface wlan1 inet dhcp

But It is changing different if I boot livecd.iso via NFS.

/etc/network/interfaces after boot via NFS(Network File System):

auto lo
iface lo inet loopback
auto eth0
iface eth0 inet manual
auto wlan0
iface wlan0 inet manual
auto eth1
iface eth1 inet manual
auto wlan1
iface wlan1 inet manual

I'm really confused. What is changing the network interfaces? How can I prevent the changes?

Note: After some research, someone pointed me /etc/udev/rules.d/70-persistent-net.rules file. It was empty. I removed it and created livecd.iso again but same things happened.

Eyüp Alemdar

Posted 2014-03-11T21:11:05.357

Reputation: 35

If you boot from a different media (e.g. a livedisc as opposed to a long-term installation on a hard disk), the filesystem root (/) is likely to be different. Those aren't the same /etcs; neither are their contents the same. – Blacklight Shining – 2014-03-11T21:31:16.300

I copied my whole OS (ubuntu 12.04 system) to NFS. It has the same interface configuration. But It is changing as I described last configuration (iface eth0 inet manual ...) when boot this OS copy via NFS. I really don't understand what is wrong with NFS. Before anything else I use same livecd.iso but see different changes. So I think it is not about the live cd and its contents place. – Eyüp Alemdar – 2014-03-11T22:15:08.917

Best asked in the Ubuntu space. – Julian Knight – 2014-03-11T22:36:11.150

@JulianKnight This doesn't seem Ubuntu-specific to me. Then again, I could be missing something. – Blacklight Shining – 2014-03-14T23:23:05.073

Might /etc/network/interfaces be being modified by NetworkManager or something similar? – Blacklight Shining – 2014-03-14T23:30:16.093

I didn't install network manager but in fact relinux changes something when create a live cd from existing installation. It thinks that network manager is installed in OS system even if it isn't. Does network manager change interfaces depending on where live cd is loading from? – Eyüp Alemdar – 2014-03-14T23:52:48.303

No answers