On 02/01/2013 08:26 AM, Filip Korzeniowski wrote:
Dear list,
I am getting strange problems using a setup outlined in the subject. I
want to run three guests on a single kvm host. The guests are connected
through macvtap directly to the network device 'eth0' of the host using
this configuration:
<interface type='direct'>
<mac address='52:54:00:86:3f:24'/>
<source dev='eth0' mode='bridge'/>
<address type='pci' domain='0x0000' bus='0x00'
slot='0x03' function='0x0'/>
</interface>
Each guest is assigned a static ip address, no DHCP is involved.
When I start the guests the macvtap links are generated automatically,
ifconfig outputs this:
macvtap2 Link encap:Ethernet HWaddr 52:54:00:86:3f:24
inet6 addr: fe80::5054:ff:fe86:3f24/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:98 errors:0 dropped:0 overruns:0 frame:0
TX packets:31 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:500
RX bytes:10946 (10.6 KiB) TX bytes:2184 (2.1 KiB)
However, depending on the startup order, only the first two guests are
able to reach the network! I can't access the third one. After the
initial startup, the last host won't connect to the network even if I restart
all the guests in a differnt order. I can only reset this by restarting
the host.
Assuming that each guest's interface definition has a unique MAC
address, this really sounds like a bug in macvtap on your kernel. There
is probably some limit on the number of macvtap interfaces attached to a
single physical interface, but it's certainly much higher than 3, and if
you hit it you'd be more likely to get an error when attempting to
create the macvtap device.