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eth0 Does Not Show Up In Some Installations

Posted: 26. Aug 2009, 13:31
by aanastasiou
Hello All

Perhaps the title does not summarise well what i am experiencing so here is the problem:

I have installed Virtual Box (VB) on a machine (Let's call it System A) with WinXP as the host and a basic installation of Debian as the guest operating system.
In this installation i have two interfaces enabled, eth0 and eth1. eth0 is NATed and provides internet access to the host (which i only need for installing some additional packages), eth1 is set to the 'Internal Network' mode and gets assigned the IP: 192.168.56.2. Once up, this enables the host operating system to connect to whatever servers run on the guest OS through this network.

The image for this installation was put on a USB disk. I then moved to another system running WinXP (Let's call this System B), installed VB, created a virtual machine and pointed it to the.vdi on my portable USB disk.
In this case, the guest OS boots normally but only eth1 shows up. eth0 acts as if it is not even present (device not found kind of message). On the other hand, eth1 seems to be behaving normally but once up it can not even ping the host OS giving the error that the network is unreachable (they both are on the same network, have the same network mask and VB shows the NIC as having it's...virtual cable, connected).

This exact same behaviour was also observed when i moved on to yet another machine (Let's call this one System C also running winXP). And this was the point when i decided to ask about this on this forum.

System A is an Intel 2.4GHz dual core with 4GB of memory, System B is a Dell Inspiron Laptop at 1.5Ghz with 512MB of memory, System C is an AMD Athlon 1.3GHz with 1GB of memory. All of them running WinXP as the host OS and are completely updated.
(As a note, the virtual installation was performing well even in the less capable systems where the CPU was peaking at about 65%. This was roughly tested at the host system with apache2, mysql and some scripts in python-django...)

Does this sound as a 'Virtualbox settings' or 'Host system hardware' problem?

Re: eth0 Does Not Show Up In Some Installations

Posted: 26. Aug 2009, 13:50
by Sasquatch
Linux creates new interface names if the MAC address is different. Issue an ifconfig -a to see all known interfaces. You have to set the same MAC address on all systems where you use the VDI, or if they aren't shared using one storage (like an external hard drive), remove /etc/udev/rules.d/70-persistent-net.rules in each system, reboot the Guest and it generates a new rules file, with a new eth0 and eth1.

Re: eth0 Does Not Show Up In Some Installations

Posted: 26. Aug 2009, 18:25
by aanastasiou
Hello Sasquatch

Thank you very much for the rapid response. Indeed, once i matched the MAC addresses across the machines, the interfaces 'came back'.

A couple of notes:

1) Prior to changing anything, ifconfig -a was only listing the loopback and eth1 interfaces. Additionaly, eth1 was always down and had to be activated manually.

2) (After matching the MAC Addresses) --> Unfortunately, when i set eth1 to the internal network it still does not seem to be communicating with the host :-/ .....There is not even any network activity and when eth1 goes 'up', dmesg does not report anything strange.

I will continue dealing with #2 but i would like to thank you very much again for your help.

All the best

All the best