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I am using ubuntu 10.04 (Bio-linux 6.0). Last night I tried leaving my system in hibernate mode because there appears to be a bug in this version of ubuntu such that if I do a straight shut-down, the machine will boot up by itself some time overnight.

This morning I could not bring the system back up from hibernate so had to hold down the power button to reset. Upon restarting I found my network connections (wired) had disappeared. I eventually found the following code online:

sudo service network-manager stop
sudo rm /var/lib/NetworkManager/NetworkManager.state
sudo service network-manager start

Fortunately running this code returned my auto eth0 connection. However, I used to also have a connection called auto eth1, and this appears no longer to be present.

My question therefore has three parts:

  • What is auto eth1?
  • Do I need to get it back?
  • How do I get it back?
share|improve this question
to assist with diagnosis, please provide output of ifconfig and cat /proc/net/dev. also cat /etc/udev/rules.d/70-persistent-net.rules – cas Aug 1 '12 at 10:07
If you have both eth0 and eth1, it means you have two wired Ethernet connections. How did you configure them? What doesn't work now? By the way, if your machine boots on its own, it's probably a BIOS bug, not an OS bug. – Gilles Aug 1 '12 at 23:01
Thanks @Gilles,I didn't do anything to configure them. I think both must have been automatically configured when I first installed bio-linux on my machine, which I did with the network cable plugged in. My internet connection works fine at the moment (presumably via eth0), the only difference is that eth1 no longer appears in my list of network connections. I'm not even sure if this is a problem as it doesn't appear to inconvenience me in any way. Apologies not to be able to be clearer, am relatively new to linux and using it in my university department. – Nick Aug 3 '12 at 10:41
@CraigSanders,sorry if this comes across as naive but is there any security risk to publishing this info online? What I could do instead is run these commands on my machine and on the machine next to me (which still has eth0 and eth1 connections) and compare them. Would this tell me anything? – Nick Aug 3 '12 at 10:51
@Nick If you have a single cable plugged into the machine, only one of eth0 or eth1 should be active. There is no security risk in publishing what Craig asked for, except that your IP addresses and MAC addresses will be exposed, so you may want to replace them with “dummy” values. IP addresses of the form 10.x.y.z, 127.x.y.z, 172.x.y.z with 16≤x≤31 and 192.168.y.z are local addresses so revealing them will not violate your privacy. – Gilles Aug 3 '12 at 11:42

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