A maybe bug when testing vlan function in Nova+Quantum+Openvswitch

My environment includes two physical hosts.
One of them (domain name cc201) installed all of nova components and Glance, Quantum, Keystone, Horizon, Open-vSwitch as controller and network node; the other installed only nova-compute, Quantum, Open-vSwitch as compute node.

also I run quantum-agent, load 8021q module.etc
Everything seems runs well.
But I found a curious problem!

On cc201, I create networks 192.168.153.0/24(network3, its vlan ID is 6)、192.168.155.0/24(network5, its vlan ID is 8)
I run nova-manage on host cc201 to create VMs.
the VMs are:
192.168.153.2 (on host cc201)
192.168.153.4 (on host cc202)
192.168.153.5 (on host cc202)
192.168.153.6 (on host cc202)
192.168.155.2 (on host cc201)
192.168.155.3 (on host cc201)
192.168.155.4 (on host cc202)

I log on one of them to ping another of them and capture packets through eth1(eth1 interface the openvswitch port on both of my hosts cc201 and cc202, by using command ovs-vsctl add-port eth1 br-int), results are as below:

I run tcpdump -i eth1 -v -w to capture and save packets
when I log on 192.168.153.2 (on cc201, in vlan6):
ping 192.168.153.4 (on cc202, in vlan6): (result is they connected)
on eth1 of cc201:I can see vlan 6 tag in ICMP request and reply, it is what I expected
on eth1 of cc202:I can see vlan 6 tag in ICMP request and reply, it is what I expected

when I log on 192.168.153.2 (on cc201, in vlan 6):
ping 192.168.155.2 (on cc201, in vlan8): (result is they are not connected)
this result is also what I expect

But when I log on 192.168.153.2 (on cc201, in vlan 6)
ping 192.168.155.4 (on cc202, in vlan 8): (result is they connected!!!)
on eth1 of cc201: I cannot see vlan 6 tag in ICMP, instead, I can see vlan 8 tag in ICMP request and reply!!!
on eth1 of cc202: I cannot see vlan 6 tag in ICMP, instead, I can see vlan 8 tag in ICMP request and reply!!!
another words, it has the wrong vlan tag! (expect 6 but actually 8!)

so what happened ? Is this a known bug of quantum or openvswitch?

more details is as below:
1)nova config on cc201: nova.conf--http://paste.openstack.org/show/18588/
nova-compute.conf--http://paste.openstack.org/show/18589/
2)nova config on cc202: nova.conf--http://paste.openstack.org/show/18590/
nova-compute.conf--http://paste.openstack.org/show/18591/
3)other command results on cc201--http://paste.openstack.org/show/18592/
4)other command results on cc202--http://paste.openstack.org/show/18593/