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  1. #1

    ICMP Signal works, 5 seconds later it doesn't work?

    Hello Forum Users

    I wrote recently about my problem, but I had luck and restore the environment doesn't work.

    My System is a physical Server with Suse Enterprise Server, and a virtual Machine with a Ubuntu Server.

    I try the net structur just with a ICMP Signal by now.

    my config about my Problem is following:

    pyhsical machine: eth1; >virtual bridge: br0,> virtual nic:vnet1 (subnet 1)

    this going to transfer in eth0 in the virtual machine


    eth1 in the virtual machine

    then through ;
    virtual nic: vnet0; > virtual bridge: br1; >physical machine: eth0 (subnet2)

    First off all my communication between brX and vnetX (this ones in the same subnet) just works if I flush the iptables rules, generated by libvirt.

    Then the problem:

    I ping between br0 and vnet1: It's work! 5 seconds later. It isn't work but then I can ping between br1 and vnet0. And the other way not work.

    My problem also that all my nics: ethX, brX and vnetX are permanent going down or disappear completely. This with tipping the command:
    „ip addr show“ And I don't now how I get them to stay.

    It is a arp Problem? I read about but I don't understand it until now.

    My result of brctl show:

    bridge name  stp enabled  interfaces
    br0		    no	             eth1
    br1		    no		      eth0
    virbr0	        yes         virbr0-nic
    I have tried to take away the bridge virbr0 for testing, and start my VM with a few network parameters in the xml file, but then my virtual machine doesn't start. But there must a way to do this, or is this wrong.

    I know there are to ways to connect VM's:
    With a normal bridge (br) and a virtual bridge (virbr).

    Thank you Flo

  2. #2
    Hi Forum Users,

    The bridges doesn't work reliable if the nic's it build of, vnetX and ethX not wired with a partner. I have no wire in my physical ethX. It's mean there was no wire to my router.

    But now following:

    I have a successfully ICMP signal which forwarding in my virtual machine.

    When I use following command:

    ping -I 192.168.2.x  192.168.178.y
    I ping from one bridge to the other one. Through my VM.

    But now it's away again.

    I don't no why?

    Now I can ping from br0 to br1 without it recognized from my forwarding iptable rule in my virtual machine. And both br0 and br1 are in different subnets.

    I have no forwarding activ in my physical server.

    Thank you for reading,

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