This is an archived copy of the Xen.org mailing list, which we have preserved to ensure that existing links to archives are not broken. The live archive, which contains the latest emails, can be found at http://lists.xen.org/
Home Products Support Community News


Re: [Xen-users] DHCP problem when changing motherboard

Subject: Re: [Xen-users] DHCP problem when changing motherboard
From: Evan Lavelle <sa212+xen@xxxxxxxxxxx>
Date: Mon, 13 Jul 2009 15:21:27 +0100
Cc: Xen <xen-users@xxxxxxxxxxxxxxxxxxx>
Delivery-date: Mon, 13 Jul 2009 07:22:31 -0700
Envelope-to: www-data@xxxxxxxxxxxxxxxxxxx
In-reply-to: <AEC6C66638C05B468B556EA548C1A77D016DDC51@trantor>
List-help: <mailto:xen-users-request@lists.xensource.com?subject=help>
List-id: Xen user discussion <xen-users.lists.xensource.com>
List-post: <mailto:xen-users@lists.xensource.com>
List-subscribe: <http://lists.xensource.com/mailman/listinfo/xen-users>, <mailto:xen-users-request@lists.xensource.com?subject=subscribe>
List-unsubscribe: <http://lists.xensource.com/mailman/listinfo/xen-users>, <mailto:xen-users-request@lists.xensource.com?subject=unsubscribe>
References: <4A5B0943.1050507@xxxxxxxxxxx> <AEC6C66638C05B468B556EA548C1A77D016DDC51@trantor>
Sender: xen-users-bounces@xxxxxxxxxxxxxxxxxxx
User-agent: Thunderbird (Windows/20090605)
I think what I'm seeing is what I'd expect on switching from xenbr0 to virbr0. The libvirt/dnsmasq defaults seems to be to create a local 192.168.122 subnet, with no access in from outside, and (external) DHCP disabled.

I don't want to mess with libvirt, since I don't use the XML config stuff and I don't want to move away from my known good setup prior to my motherboard change, so I'm concentrating on finding out why xenbr0 no longer works.

If I boot up a DomU with xenbr0 in the vif line I get:

Error: Device 0 (vif) could not be connected. Could not find bridge device xenbr0.

What I think has happened is that the existing fc8-xen on my hard drive is confused about the network hardware on the new motherboard (a Dell R200 server). When the new board originally booted up, networking was disabled, but I fixed this by aliasing eth0 to eth3. The (old) driver seemed to have identified the new NICs at eth3 and eth4, rather than eth0/1. Anyway, that fixed the network on Dom0, but it seems to be giving Xen a headache when it boots any DomU's. The DomU's boot up Ok with virbr0; the problem is just xenbr0.

I know that FC8 had bugs in the network-bridge script related to aliasing, but network-bridge runs without producing errors, so I'm not convinced that that's the problem here.



Xen-users mailing list