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My box encounter a power failure. After booting again, the ubuntu server (which I installed on the box) does not automatically acquire a Network IP (I didn't set a LAN-static ip for that box - the IP is generated by a router). I'm getting freaking because I cannot find a usb keyboard around the place (everyone at my place is using ps2 keyboard which my box does not support any more).

I'm gonna bring it back to my friend house to have thing fixed. However, can anyone help explaining why my Ubuntu 10.04 does not acquire an IP after a power failure? How can I prevent this behavior?

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up vote 2 down vote accepted

After power failure, the observed identity of my NIC changed, result in a new eth1 device being created, which in turn creates the mess. I edited the /etc/udev/rules.d/70-persistent-net.rules (as described in my another question here: and rebooted the box. The problems has gone away. Thank you guys for helping.

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You might want to look for an usb2ps2 cable like this:

alt text

There are many possible scenarios in your situation, like:

  • filesystem got corrupted due to power failure, the boot scripts that take care of the networking part are broken
  • your NIC got toasted and you'll have to replace it (this is ugly, but it happens sometimes)

But frankly, get yourself an UPS if you don't have one yet, it protects against sudden power failures.

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That sounds horrible. I have just purchased the box a few days ago. – Phuong Nguyen Aug 18 '10 at 14:52

How do you know it doesn't have an IP? If you're trying to connect to some service on it perhaps that service wasn't set to startup on reboot?

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My DHCP will allocate IP -> to every machine on the network. But I cannot ping to the machine through any of the IP in the range, except the which my current laptop already take it. – Phuong Nguyen Aug 18 '10 at 14:52
Does your DHCP server have a web interface so that you could check whether the IP has been given out (maybe ping is being blocked by a firewall)? – JustinP Aug 18 '10 at 15:08
Well, I have setup this machine and I know that this machine is ping-able, ssh-able. But I cannot scan for it on the network through a linux ip scanning program. – Phuong Nguyen Aug 18 '10 at 16:46


Does /var/log/messages give you any insight into what the dhcp-client is attempting to do?

If you don't have that information, its possible that dhcp-client is attempting to reacquire its old lease, but the DHCP server might be configured to prevent that from happening. You might need to check which options are enabled for dhcp-client.

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