hello, virsh iface-bridge to build bridge interface does not work for me,i've searched in google but got nothing ,please give some help,thanks. # VIRSH_DEBUG=0 VIRSH_LOG_FILE=bridge.log virsh iface-bridge eth0 br0 iface-bridge: found option <interface>: eth0 iface-bridge: <interface> trying as interface NAME libvir: Interface error : Interface not found: couldn't find interface named 'br0' libvir: Interface error : internal error could not get interface XML description: XSLT transformation failed - runtime error: file /usr/share/netcf/xml/initscripts-get.xsl line 196 element node error: Failed to define new bridge interface br0 error: internal error could not get interface XML description: XSLT transformation failed - runtime error: file /usr/share/netcf/xml/initscripts-get.xsl line 196 element node # virsh version Compiled against library: libvir 0.9.10 Using library: libvir 0.9.10 Using API: QEMU 0.9.10 Running hypervisor: QEMU 0.12.1 # cat bridge.log [2012.08.16 16:16:50 virsh 10895] INFO iface-bridge: found option <interface>: eth0 [2012.08.16 16:16:50 virsh 10895] DEBUG iface-bridge: <interface> trying as interface NAME [2012.08.16 16:16:50 virsh 10895] ERROR Failed to define new bridge interface br0 [2012.08.16 16:16:50 virsh 10895] ERROR internal error could not get interface XML description: XSLT transformation failed - runtime error: file /usr/share/netcf/xml/initscripts-get.xsl line 196 element node this is some debug log from /var/log/libvirt/libvirtd.log: 2012-08-16 08:54:25.724+0000: 11526: debug : virInterfaceDefineXML:10794 : conn=0x7f963c0009c0, xml=<?xml version="1.0"?> <interface type="bridge" name="br0"> <start mode="onboot"/> <protocol family="ipv4"> <ip address="118.123.12.65" prefix="25"/> <route gateway="118.123.12.1"/> </protocol> <bridge stp="on" delay="0"><interface type="ethernet" name="eth0"><mac address="00:30:48:D9:F7:EE"/></interface></bridge></interface> , flags=0 2012-08-16 08:54:25.724+0000: 11523: debug : virEventPollCleanupTimeouts:506 : Cleanup 3 2012-08-16 08:54:25.724+0000: 11523: debug : virEventPollCleanupHandles:554 : Cleanup 8 2012-08-16 08:54:25.724+0000: 11523: debug : virEventPollMakePollFDs:383 : Prepare n=0 w=1, f=7 e=1 d=0 2012-08-16 08:54:25.724+0000: 11523: debug : virEventPollMakePollFDs:383 : Prepare n=1 w=2, f=9 e=1 d=0 2012-08-16 08:54:25.724+0000: 11523: debug : virEventPollMakePollFDs:383 : Prepare n=2 w=3, f=12 e=1 d=0 2012-08-16 08:54:25.724+0000: 11523: debug : virEventPollMakePollFDs:383 : Prepare n=3 w=4, f=13 e=1 d=0 2012-08-16 08:54:25.724+0000: 11523: debug : virEventPollMakePollFDs:383 : Prepare n=4 w=5, f=6 e=1 d=0 2012-08-16 08:54:25.724+0000: 11523: debug : virEventPollMakePollFDs:383 : Prepare n=5 w=6, f=16 e=1 d=0 2012-08-16 08:54:25.724+0000: 11523: debug : virEventPollMakePollFDs:383 : Prepare n=6 w=7, f=15 e=1 d=0 2012-08-16 08:54:25.724+0000: 11523: debug : virEventPollMakePollFDs:383 : Prepare n=7 w=8, f=17 e=1 d=0 2012-08-16 08:54:25.724+0000: 11523: debug : virEventPollCalculateTimeout:325 : Calculate expiry of 3 timers 2012-08-16 08:54:25.724+0000: 11523: debug : virEventPollCalculateTimeout:351 : Timeout at 0 due in -1 ms 2012-08-16 08:54:25.724+0000: 11523: debug : virEventPollRunOnce:619 : EVENT_POLL_RUN: nhandles=8 imeout=-1 2012-08-16 08:54:25.730+0000: 11526: error : interfaceDefineXML:425 : internal error could not get interface XML description: XSLT transformation failed - runtime error: file /usr/share/netcf/xml/initscripts-get.xsl line 196 element node thanks.