Disable/stop Nic In A Virtual Guest With Virsh

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Hi all,

How can I stop/disable a nic in a virtual guest using a virsh command?? I am searching the same effect like if I unplug network cable … Is it possible?? I have tried with “detach-interface”
command without luck. I don’t want to remove the nic from guest configuration, only to stop the nic …

Thanks.

P.D: Host is CentOS 6.6 x86_64 fully patched.

5 thoughts on - Disable/stop Nic In A Virtual Guest With Virsh

  • I don’t think it can be done. I would try to remove the VM’s vnet from the bridge it’s connected to.

    HTH
    Lucian

  • Depending on your network architecture you could just ifdown the vmnet, but this just works if you don’t have multiple vms on one vmnet (which you shouldn’t).

    HTH


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    Sven Kieske

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  • There’s a qemu monitor command for that. You can pass it in through virsh:

    $ virsh qemu-monitor-command –hmp ‘set_link off’

    Example:
    # virsh list Id Name State
    ————————————————–

  • * Definitely look to Juerg Haefliger’s solution. It’s exactly what you want since you requested a method that can be done from the virsh interface. Thanks Juerg!

    1) down the vnetX interface from the host node
    ip link show dev vnetX
    ip link set down vnetX
    ip link show dev vnetX

    And if using bridged networking, you have one more option.
    2) remove the vnetX interface from the bridge
    brctl delif vnetX

    Certainly downing the interface using either Juerg’s solution via virsh or mine via iproute2 tools is most ideal since it’s easier/simpler to reinstate. You can use ifconfig if you prefer it over ip tools, but enjoy those tools and syntax while it remains! [0] ;-)

    [0]
    https://dougvitale.wordpress.com/2011/12/21/deprecated-linux-networking-commands-and-their-replacements/