[libvirt] About the qemu networking

Dear libvirt team, I am testing the qemu with libvit networking, and I have a question. First, I connected the switch and server via Ethernet, the link encapsulation is 802.1q (eth1 is trunk link) When I use sub-interface eth1.12 for vlan12,br12 bridged to eth1.12, and then using tap0 ..tapN, the qemu guest networking works fine. But when I use br1 bridged to eth1 without sub-interface, also use tap0… tapn , it does not work. The topology as below: This works fine This doest not work Eth1 (trunk) eth1(trunk) | | | -------------- ----------------- | | | br1 Eth1.12 eth1.13 … | | | _______________ br12 br13 | | | | | … | | | tap0 tapn --------- ---------- | | | ... | | | | | Tap0 … tapn tapn+1 tapm Is the second solution works ? if works? What should I do to ? Thanks very much, I am look forward to hear from you. Best Regards 杨树林 技术保障中心 网络工程师 snda 上海盛大网络发展有限公司 上海浦东新区碧波路690号1号楼 邮编：201203 电话：021-50504740-896570 传真：021-50504740-895746 Email：yangshulin(a)shandagames.com 网址：http://www.snda.com