Already reported.... http://bugs.centos.org/view.php?id=2516 >Subject: RE: [CentOS-virt] xenbr0 isn't created anymore >To: <centos-virt at centos.org> >Message-ID: > <E2BB8074E5500C42984D980D4BD78EF9022A704E at MFG-NYC-EXCH2.mfg.prv> >Content-Type: text/plain; charset="us-ascii" > >Kai Schaetzl wrote: >> >> Somehow I managed to disable the creation of xenbr0 on boot-up of the host >> system. CentOS 5 with standard CentOS Xen. >> I changed all Xen VMs to use xenbr0 instead of virbr0 and disabled >> virtlibd. Works fine. But when I later restarted the machine I found that >> all networking for guests had gone. On inspection there's no xenbr0 >> created anymore. I can get it up by stopping network (or eth0) and then >> running /etc/xen/scripts/network-bridge start >> xend-config.sxp still has (network-script network-bridge), logging shows >> no problems. It seems that the network-bridge script simply doesn't run, >> but why? I can't see any init script or so that might run it, so I assume >> it's xend doing that, but there's no error in any log. > >Kai, > >Snooping around I found this in /etc/xen/qemu-ifup: > ># ># Old style bridge setup with netloop, used to have a bridge name ># of xenbrX, enslaving pethX and vif0.X, and then configuring ># eth0. ># ># New style bridge setup does not use netloop, so the bridge name ># is ethX and the physical device is enslaved pethX ># ># So if... ># ># - User asks for xenbrX ># - AND xenbrX doesn't exist ># - AND there is a ethX device which is a bridge ># ># ..then we translate xenbrX to ethX ># ># This lets old config files work without modification > >So it turns out Xen networking changed in current releases and they never >updated their Wiki. > >Now I am not sure how the vif0.X and vethX interfaces fit into the >picture here... Maybe these are no longer used? > >vifX.Y interfaces are still used though for linking domU interfaces >with the physical interface. > > >-Ross > >______________________________________________________________________ >This e-mail, and any attachments thereto, is intended only for use by >the addressee(s) named herein and may contain legally privileged >and/or confidential information. If you are not the intended recipient >of this e-mail, you are hereby notified that any dissemination, >distribution or copying of this e-mail, and any attachments thereto, >is strictly prohibited. If you have received this e-mail in error, >please immediately notify the sender and permanently delete the >original and any copy or printout thereof. > > >