Consider whether you're talking about layer 2 or layer 3 network connectivity (test). If this is a Workgroup, consider whether you have a Browse Master issue. Consider whether your issue is a name resolution issue. I assume the connection is bridged? Try NAT if it doesn't make a diff to you.
Tony On Mon, Aug 24, 2015 at 7:29 AM, Vlad Yasevich <vyase...@redhat.com> wrote: > On 08/23/2015 07:31 AM, Davide Baldini wrote: >> Thanks Vlad, >> > .. snip.. >> >> As far as I notice, there are no differences shown by `ifconfig`. >> The fact is, that all guests drop the network after a cable is unplugged and >> then >> replugged, while the host's network keeps functioning. > > What do you mean by "drop network"? Is the link going down in the guest? Is > the guest losing IP address? Is the guest simply stops being reachable? > > Are there any firewall rules on the host? > > Thanks > -vlad > >> >> Where else can I look? >> >> -- Davide >> >> On 08/19/2015 08:02 PM, Vlad Yasevich wrote: >>> On 08/16/2015 12:55 PM, Davide Baldini wrote: >>>> When I unplug the ethernet cable from the physical host, guest fails to >>>> reconnect; host >>>> does reconnect. >>> >>> What do you mean by 'reconnect'? Unplugging the cable for the nic on the >>> physical host >>> does not really disconnect the guest from the network. According to the >>> configuration >>> your provided, the guest is still connected to the bridge on the host and >>> can still >>> communicate with other guests on the same host. >>> >>> Once the host network is plugged back in, the bridge should start >>> forwarding packets >>> back to the guest. >>> >>>> >>>> A very simple configuration here, with an almost default Debian 7 on both >>>> host and guest: >>>> >>>> -- ON HOST: >>>> >>>> /etc/network/interfaces >>>> >>>> auto lo >>>> iface lo inet loopback >>>> >>>> auto br0 >>>> iface br0 inet dhcp >>>> bridge_ports eth1 >>>> bridge_stp off >>>> bridge_maxwait 0 >>>> bridge_fd 0 >>>> >>>> >>>> -- ON GUEST: >>>> >>>> /etc/network/interfaces >>>> >>>> auto eth0 >>>> allow-hotplug eth0 >>>> iface eth0 inet static >>>> address 192.168.1.109 >>>> netmask 255.255.255.0 >>>> network 192.168.1.0 >>>> broadcast 192.168.1.255 >>>> gateway 192.168.1.1 >>>> dns-nameservers 192.168.1.1 >>>> >>>> >>>> QEMU is started as: >>>> >>>> /usr/local/bin/qemu-system-x86_64 -hda /media/raid1/qemu-109 -m 8G -smp 4 >>>> -enable-kvm >>>> -netdev bridge,id=br109 -device >>>> virtio-net-pci,netdev=br109,id=nic0,mac=00:00:00:00:01:09 >>>> -k it -daemonize >>>> >>>> QEMU emulator version 2.3.0 >>>> >>>> Nothing appears on dmesg. Any hints? >>> >>> Make sure that the bridge on the host is formed correctly after the cable >>> has been plugged >>> back in. >>> >>> -vlad >>> >>>> >>>> -- Davide >>>> >>> >> > >