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I’m having a strange networking problem with a Debian (6) VMWare virtual machine on my Mac. Around 15 minutes after starting it up, I can no longer SSH into, view websites served from, or ping the VM.

I usually run the VM in headless mode, using vmrun -T fusion start VIRTUALMACHINEPATH nogui, but the problem occurs when I start the virtual machine via too.

When I use ifconfig to check the machine’s IP address once the network connections have failed (which I do via the GUI — launching after the server is inaccessible in headless mode gives me a GUI access to the server), the following line is missing:

 inet addr:  Bcast:  Mask:

(This line is present when I boot up; it disappears after the network connections go down.)

This started happening yesterday, seemingly for no reason — the VM’s been running fine for a couple of weeks. I installed rsync on the VM yesterday, and was writing some Python code that used subprocess to start Xvfb and Selenium Server. I don’t know if that code somehow managed to permanently bork networking on the VM.

I’ve tried copying the .vdmx files and opening them in a VirtualBox virtual machine. The network issue doesn’t seem to happen there (i.e. the inet addr line in ifconfig stays present for over an hour); however, VirtualBox VMs don’t by default make the virtual machine accessible on the network, whereas VMWare seems to do so. I haven’t figured out how to turn on NAT port forwarding for incoming connections to the VirtualBox VM in the same way that VMWare is set up. (Both my VMWare and VitualBox virtual machines use NAT for networking.)

I’m a total networking idiot, so I don’t know if this is a VMWare issue, something I’ve managed to do in Linux, or some sort of random external attack — hence the cross-posting.

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Please do not cross-post your questions on Super User and Server Fault. – nhinkle Apr 18 '11 at 21:41

We had a similar issue on Debian squeeze, where-in once "ifconfig .... down" was done, and then immediately "ifconfig... up" was done, the configured IP address info wasn't available any longer.

Stopping the network-manager helped us. Try it:

/etc/init.d/network-manager stop
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I’ll have a look, cheers. – Paul D. Waite Jun 10 '11 at 12:19

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