Re: No IP address in virtual machine

[Manuel Bouyer <bouyer%antioche.eu.org@localhost>]

On Thu, Apr 02, 2009 at 08:31:00PM +1100, Christian Lerrahn wrote:
> Hi,
> I've set up a NetBSD 5.0RC2 system which runs a XEN PV. The XEN packages
> installed are
> 
> xenkernel33-3.3.0nb1 Xen 3.3.0 Kernel
> xentools33-3.3.0nb4 Userland Tools for Xen 3.3.x
> 
> I've now set up a virtual machine using a Debian 4.0 (64bit) image from
> http://jailtime.org and a Debian distro XEN kernel with it. The machine
> boots fine and the network also looks ok in xm network-list. However, I
> will never get an IP address even though the machine is configured to
> use DHCP.
> 
> Here is the xm network-list for the virtual machine.
> 
> Idx BE     MAC Addr.     handle state evt-ch tx-/rx-ring-ref BE-path
> 0   0  00:16:3e:5b:d1:6e    0     4      7   521  /522     
> /local/domain/0/backend/vif/2/0
> 
> The configuration file is as follows.
> 
> kernel = "/home/debian-4.0/boot/vmlinuz-2.6.18-4-xen-amd64"
> memory = 256
> name = "debian.4-0.64"
> vif = [ 'bridge=bridge0' ]

Does bridge0 exists in dom0 ?

> dhcp= "dhcp"
> disk = ['file:/home/debian-4.0/debian.4-0.64.img,sda1,w']
> root = "/dev/sda1"
> extra="TERM=vt100 xencons=tty console=ttyS0"
> ramdisk="/home/debian-4.0/boot/initrd.img-2.6.18-4-xen-amd64"
> 
> Here is what concerns eth0 in the dmesg of the virtual machine.
> 
> debian-pristine:~# dmesg | grep eth0
> Bootdata ok (command line is root=/dev/sda1 ip=:127.0.255.255::::eth0:dhcp 
> TERM=vt100 xencons=tty console=ttyS0)
> Kernel command line: root=/dev/sda1 ip=:127.0.255.255::::eth0:dhcp TERM=vt100 
> xencons=tty console=ttyS0
> netfront: device eth0 has flipping receive path.
> eth0: no IPv6 routers present
> 
> The XEN logs all look normal. The only error message I see is
> in /var/log/xen/xend-debug.log.
> 
> brctl: not found
> 
> I'm happy to send everything I find in /var/log/xen/xend.log if
> anyone believes that might be helpful. I'm running a XEN debug
> kernel, so there is a bit of output there. But as mentioned
> above, nothing looks like anything going wrong.

You could also try running tcpdump on the xvif interface in dom0 and
see if the domU is sending any packet.

There has also been case where the issue was a hardware checksum setting
mismatch between dom0 and domU (the  domU thinking the dom0 would build the
checksum and the dom0 rejecting the packet because the checksum is
wrong)

-- 
Manuel Bouyer <bouyer%antioche.eu.org@localhost>
     NetBSD: 26 ans d'experience feront toujours la difference
--