Ubuntu 8.04 networking gone after 4.0 update

Discussion in 'Linux Guest OS Discussion' started by cliffom, Nov 13, 2008.

  1. cliffom

    cliffom

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    5
    I had zero issues converting my ubuntu 8.04 server vm from 3.0 to 4.0, however when I start up shared networking is not working.

    The output of ifconfig only lists the 'lo' interface. I have also attached a screengrab of the output of dhclient eth0.
     

    Attached Files:

  2. cliffom

    cliffom

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    5
    Nevemind, I checked the output of dmesg and saw that eth0 was renamed to eth1. No idea why this happened.
     
  3. Elric

    Elric Parallels Developers

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    1,579
    This is due to change of MAC-address of the VM-adapter. If open the VM configuration and change MAC Address of the VM Network Adapter one more time, iface name will become eth2

    But until MAC is changed, eth1 will be same eth1. If you remember your old MAC address you can enter it in the VM configuration and card will be again eth0

    There is some way to reset the numbering of units back again, but I can't say how at the moment..
     
  4. graham@capgo.com

    graham@capgo.com

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    I too have this problem where eth0 appears to have been (partly) bumped to eth1 and causing Ubuntu to become somewhat confused. Setting to exclusively eth0 or eth1 in dhclient.config and /etc/networks/interfaces does not resolve the problem. Network Tools - Devices only ever shows eth1, so there is obviously another place defining its eth1.

    Interestingly:
    ifconfig shows eth1 and lo with sensible looking data, but there is no eth0
    ifup eth1 returns "Ignoring unknown interface ...."
    ifup eth0 returns "ERROR while getting interface flags: No such device ...."

    So, cliffom, or anyone can point me in the right direction I would be grateful
     
  5. Elric

    Elric Parallels Developers

    Messages:
    1,579
    The eth0 was renamed to eth1 due to change of Network Adapter MAC-address. If you know your previous MAC, you can edit VM configuration and set NetworkAdapter to use old MAC. This should make network interface be eth0 back.

    The change of MAC address could occur while converting VM from 3.0 to 4.0 on build 3522 (there should not be such behaviour on build 3540)

    The behaviour
    ifup eth1 returns "Ignoring unknown interface ...."
    seems logical, since afaik there are scripts like ifup-eth0/ifdown-eth0, which are created while configuring system. So ifup eth1 cann't find the script ifup-eth1 and barks.

    Interface may be started manually. Probably, by command "sudo /sbin/dhclient eth1"...

    So, either eth1 need to be configured somehow (using some your linux distro utility), or MAC address should be changed to the previous address (which will make it back eth0)
     
    Last edited: Dec 12, 2008
  6. graham@capgo.com

    graham@capgo.com

    Messages:
    7
    The problem has been resolved in two ways, the first out of frustration, the second out of curiosity.

    Method 1: Build a new virtual machine, taking the opportunity to upgrade to Ubuntu 8.10. This was quick and trouble free. The hassles came in transferring my work over, but thats another story.

    Method 2: I had already read this thread before updating to 4.0, so I had recorded the MAC address. The build I am using is 3540 and I can confirm that the MAC address was not changed, however the eth0 was still incremented to eth1. This indicates the MAC address in not the cause - so there is still an issue in build 3540. Adjusting the previously mentioned files to reflect eth1 and applying Elric's "sudo /sbin/dhclient eth1" did the trick.

    I am now able to transfer files to my new Ubuntu 8.10 VM - so I am very relieved but a bit annoyed that it happened and took a days hands-on work to recover.
     
  7. John@Parallels

    John@Parallels

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    6,450
    Erlic
    Please check PM
     
  8. graham@capgo.com

    graham@capgo.com

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    By PM, do you mean power management?
    Assuming you do (although I don't understand the relevance in this context) I have configured both Pararllels and the guest OS for no sleeping, no screen saver, no battery, optimized for speed and optimized of guest OS.
     
  9. DaTa

    DaTa

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    194
    To graham@capgo.com:

    By PM John meant Private Message box. As it was addressed to Elric, I think we should not take it into consideration. So, there is nothing to do with Power management )
     
  10. John@Parallels

    John@Parallels

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    6,450
    graham@capgo.com
    This is problem with all Debian based distro, in all virtualization software we are going to investigate it
     
  11. Forgiven

    Forgiven

    Messages:
    47

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