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.