[Bug 633392] [NEW] Bridged Guests losing network connectivity

Launchpad Bug Tracker 633392 at bugs.launchpad.net
Wed Sep 15 03:19:00 UTC 2010


You have been subscribed to a public bug:

Binary package hint: qemu-kvm

Opening at the request of Serge Hallyn.


Running 10.04 with KVM and Libvirt, starting VMs with "virsh start <domain>"

I've tested with OpenBSD 4.7 and Debian Lenny 5.0.5, both of them are
having this issue.

I notice that networking with the bridge works fine at first for my
guests, but after a while, the bridge stops functioning, and I can't
reach it via SSH, nor can I ping/ssh out.

Also, when this happens, the ARP entry on the firewall I'm using to SSH
to the guest changes from the Guest's MAC to the Host's MAC address.

On OpenBSD, if I run the /etc/netstart script to re-initialize the
interface, the bridge starts functioning again, as if I restarted the
VM, but quickly fails again (10-20 minutes). I have to reboot the Debian
machine to get networking functioning again.


Here is my /etc/network/interfaces on the host:
# The loopback network interface
auto lo
iface lo inet loopback

# The primary network interface
auto eth0
iface eth0 inet dhcp

auto br0
iface br0 inet static
 address 192.168.8.166
 netmask 255.255.252.0
 network 192.168.8.0
 broadcast 192.168.11.255
 gateway 192.168.8.1
 bridge_ports eth1
 bridge_fd 9
 bridge_hello 2
 bridge_maxage 12
 bridge_stp off


And my /etc/libvirt/qemu/networks/autostart/default.xml:
<network>
  <name>default</name>
  <bridge name="virbr%d" />
  <forward/>
  <ip address="192.168.122.1" netmask="255.255.255.0">
    <dhcp>
      <range start="192.168.122.2" end="192.168.122.254" />
    </dhcp>
  </ip>
</network>


# iptables -L
Chain INPUT (policy ACCEPT)
target     prot opt source               destination         
ACCEPT     udp  --  anywhere             anywhere            udp dpt:domain 
ACCEPT     tcp  --  anywhere             anywhere            tcp dpt:domain 
ACCEPT     udp  --  anywhere             anywhere            udp dpt:bootps 
ACCEPT     tcp  --  anywhere             anywhere            tcp dpt:bootps 

Chain FORWARD (policy ACCEPT)
target     prot opt source               destination         
ACCEPT     all  --  anywhere             192.168.122.0/24    state RELATED,ESTABLISHED 
ACCEPT     all  --  192.168.122.0/24     anywhere            
ACCEPT     all  --  anywhere             anywhere            
REJECT     all  --  anywhere             anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  anywhere             anywhere            reject-with icmp-port-unreachable 

Chain OUTPUT (policy ACCEPT)
target     prot opt source               destination


# netstat -nr
Kernel IP routing table
Destination     Gateway         Genmask         Flags   MSS Window  irtt Iface
192.168.1.0     0.0.0.0         255.255.255.0   U         0 0          0 eth0
192.168.122.0   0.0.0.0         255.255.255.0   U         0 0          0 virbr0
192.168.8.0     0.0.0.0         255.255.252.0   U         0 0          0 br0
0.0.0.0         192.168.1.1     0.0.0.0         UG        0 0          0 eth0
0.0.0.0         192.168.8.1     0.0.0.0         UG        0 0          0 br0


# brctl show
bridge name	bridge id		STP enabled	interfaces
br0		8000.00188b3e8dc0	no		eth1
							vnet0
virbr0		8000.000000000000	yes	



IFCONFIG -- With Guest OS Running
# ifconfig -a
br0       Link encap:Ethernet  HWaddr 00:18:8b:3e:8d:c0  
          inet addr:192.168.8.166  Bcast:192.168.11.255  Mask:255.255.252.0
          inet6 addr: fe80::218:8bff:fe3e:8dc0/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:236817 errors:0 dropped:0 overruns:0 frame:0
          TX packets:2654 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0 
          RX bytes:17692813 (17.6 MB)  TX bytes:362935 (362.9 KB)

eth0      Link encap:Ethernet  HWaddr 00:18:8b:3e:8d:be  
          inet addr:192.168.1.151  Bcast:192.168.1.255  Mask:255.255.255.0
          inet6 addr: fe80::218:8bff:fe3e:8dbe/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:76541 errors:0 dropped:0 overruns:0 frame:0
          TX packets:62301 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:10233726 (10.2 MB)  TX bytes:21694280 (21.6 MB)
          Interrupt:16 Memory:f8000000-f8012800 

eth1      Link encap:Ethernet  HWaddr 00:18:8b:3e:8d:c0  
          inet6 addr: fe80::218:8bff:fe3e:8dc0/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:241821 errors:0 dropped:0 overruns:0 frame:0
          TX packets:10075 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:22612242 (22.6 MB)  TX bytes:1391493 (1.3 MB)
          Interrupt:16 Memory:f4000000-f4012800 

lo        Link encap:Local Loopback  
          inet addr:127.0.0.1  Mask:255.0.0.0
          inet6 addr: ::1/128 Scope:Host
          UP LOOPBACK RUNNING  MTU:16436  Metric:1
          RX packets:4013 errors:0 dropped:0 overruns:0 frame:0
          TX packets:4013 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0 
          RX bytes:4101296 (4.1 MB)  TX bytes:4101296 (4.1 MB)

virbr0    Link encap:Ethernet  HWaddr 62:47:ad:6a:ce:a5  
          inet addr:192.168.122.1  Bcast:192.168.122.255  Mask:255.255.255.0
          inet6 addr: fe80::6047:adff:fe6a:cea5/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:0 errors:0 dropped:0 overruns:0 frame:0
          TX packets:6 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0 
          RX bytes:0 (0.0 B)  TX bytes:468 (468.0 B)

vnet0     Link encap:Ethernet  HWaddr fe:54:00:53:2d:a1  
          inet6 addr: fe80::fc54:ff:fe53:2da1/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:7445 errors:0 dropped:0 overruns:0 frame:0
          TX packets:237663 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:500 
          RX bytes:977842 (977.8 KB)  TX bytes:20968868 (20.9 MB)


# cat /etc/libvirt/qemu/networks/default.xml 
<network>
  <name>default</name>
  <bridge name="virbr%d" />
  <forward/>
  <ip address="192.168.122.1" netmask="255.255.255.0">
    <dhcp>
      <range start="192.168.122.2" end="192.168.122.254" />
    </dhcp>
  </ip>
</network>


# qemu --version
QEMU PC emulator version 0.12.3 (qemu-kvm-0.12.3), Copyright (c) 2003-2008 Fabrice Bellard


# libvirtd --version
libvirtd (libvirt) 0.7.5


# uname -a
Linux ubuntu-kvm 2.6.32-24-server #42-Ubuntu SMP Fri Aug 20 15:38:55 UTC 2010 x86_64 GNU/Linux


# cat /etc/libvirt/qemu/infra01.xml 
<domain type='kvm'>
  <name>infra01</name>
  <uuid>46597427-81ce-e696-82f1-df7d38b0cbb9</uuid>
  <memory>524288</memory>
  <currentMemory>524288</currentMemory>
  <vcpu>1</vcpu>
  <os>
    <type arch='x86_64' machine='pc-0.12'>hvm</type>
    <boot dev='hd'/>
  </os>
  <features>
    <acpi/>
    <apic/>
    <pae/>
  </features>
  <clock offset='utc'/>
  <on_poweroff>destroy</on_poweroff>
  <on_reboot>restart</on_reboot>
  <on_crash>restart</on_crash>
  <devices>
    <emulator>/usr/bin/kvm</emulator>
    <disk type='file' device='disk'>
      <driver name='qemu' type='raw'/>
      <source file='/virt//infra01.img'/>
      <target dev='hda' bus='ide'/>
    </disk>
    <disk type='block' device='cdrom'>
      <driver name='qemu'/>
      <target dev='hdc' bus='ide'/>
      <readonly/>
    </disk>
    <interface type='bridge'>
      <mac address='52:54:00:53:2d:a1'/>
      <source bridge='br0'/>
      <model type='e1000'/>
    </interface>
    <console type='pty'>
      <target port='0'/>
    </console>
    <console type='pty'>
      <target port='0'/>
    </console>
    <input type='mouse' bus='ps2'/>
    <graphics type='vnc' port='-1' autoport='yes' keymap='en-us'/>
    <video>
      <model type='cirrus' vram='9216' heads='1'/>
    </video>
  </devices>
</domain>

** Affects: linux (Ubuntu)
     Importance: High
     Assignee: Serge Hallyn (serge-hallyn)
         Status: Incomplete

-- 
Bridged Guests losing network connectivity
https://bugs.launchpad.net/bugs/633392
You received this bug notification because you are a member of Kernel Bugs, which is subscribed to linux in ubuntu.




More information about the kernel-bugs mailing list