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Accepted
Arthur Ulfeldt
Asked: 2010-09-25 13:42:52 +0800 CST

how to disable a NIC in centos

  • 772

I'm looking for a 'one liner' for a script that needs to:

  • disable eth0.
  • make it not start on boot.
  • take away its IP address
  • ensure that it does not try to use this address again.
centos networking

9 Answers

  1. Best Answer

    One liner? How about this as root?

    echo "DEVICE=eth0" > /etc/sysconfig/network-scripts/ifcfg-eth0 && service network restart

    It will remove the configuration for eth0 and replace it with something that is unconfigured.

    • 15

  2. In /etc/sysconfig/network-scripts/ifcfg-eth0 you need to have

    ONBOOT=no

    like MDMarra said but you also need to have

    NM_CONTROLLED=no

    or else the NetworkManager will boot the interface as it ignores the ONBOOT setting. Unless you don't use NetworkManager but I think it is common.

    • 10

  3. In /etc/sysconfig/network-scripts/ifcfg-eth0 you need to change ONBOOT= to no and you can delete the lines for IPADDR and NETMASK.

    After you copy the config file, you need to restart the network daemon.

    • 4

  4. No need to restart the network daemon, especially if you have other network cards that are in use. You can just do a 'ifdown eth0'.

    • 2

  5. Put alias eth0 off in /etc/modprobe.conf. This will make sure that nothing in the system can use it ever. It won't even be able to be brought up manually.

    • 2

  6. As far as I know, the correct way is to simply turn it off using the "ONBOOT" directive and to achieve that through a script you can use the following line:

    sed -i 's/^ONBOOT.*/ONBOOT=no/g' /etc/sysconfig/network-scripts/ifcfg-eth0 && service network restart
    • 0

  7. There is another one option for inexperienced people (like me). go at www.webmin.com download and install webmin.

    configure your server via a web based environment.

    • -1

  8. in case you have not found out yet... ifconfig down or up. The old ifconfig command still allows you to do plumbing /bringing a interface up or down or other options. Use to be all there was to use when Redhat first came out.

    • -1

  9. sed -i 's/^ONBOOT.*/ONBOOT=no/g' /etc/sysconfig/network-scripts/ifcfg-eno2 && service network restart

    For making it persistent.

    chattr +i /etc/sysconfig/network-scripts/ifcfg-eno2

    • -2