Xen users - Mar 2006 - newbie: suse 10.1b6 domU network problem

Hi list,

playing with SuSE 10.1 beta 6 on a x86_64 system reveals no creation of
a vif0.0 during the boot process. After the start of xend I only see the
bridge xenbr0 along with eth0 (and apart from eth1 and eth2 which are
not in use at all). Networking of Dom0 is fine.

Starting a domU produces a vifX.0 successfully, but with/out touching
the scripts in /etc/xen/ I can''t make the domU to ping anything except
itself.


Here is what I have after fresh Dom0 boot:

  lvs01:~ # brctl show xenbr0
  bridge name     bridge id               STP enabled     interfaces
  xenbr0          8000.000000000000       no

And this after starting DomU:

  lvs01:~ # brctl show xenbr0
  bridge name     bridge id               STP enabled     interfaces
  xenbr0          8000.feffffffffff       no              vif1.0


Since I am new to xen I assume I miss something crucial here. Or beta6
has a bug? Any hint for enlightment is welcome.

Thanks,

-- 

 Stephan A. Rickauer

 -----------------------------------------------------------
 Institut für Neuroinformatik          Tel: +41 44 635 30 50
 Universität / ETH Zürich              Sek: +41 44 635 30 52
 Winterthurerstrasse 190               Fax: +41 44 635 30 53
 CH-8057 Zürich                        Web:  www.ini.ethz.ch

 RSA public key: https://www.ini.ethz.ch/~stephan/pubkey.asc
 -----------------------------------------------------------


 There is no spoon.



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Stephan A. Rickauer wrote:
> playing with SuSE 10.1 beta 6 on a x86_64 system reveals no creation of
> a vif0.0 during the boot process. After the start of xend I only see the
> bridge xenbr0 along with eth0 (and apart from eth1 and eth2 which are
> not in use at all). Networking of Dom0 is fine.
> 
> Starting a domU produces a vifX.0 successfully, but with/out touching
> the scripts in /etc/xen/ I can''t make the domU to ping anything
except
> itself.
> 
> 
> Here is what I have after fresh Dom0 boot:
> 
>   lvs01:~ # brctl show xenbr0
>   bridge name     bridge id               STP enabled     interfaces
>   xenbr0          8000.000000000000       no
> 
> And this after starting DomU:
> 
>   lvs01:~ # brctl show xenbr0
>   bridge name     bridge id               STP enabled     interfaces
>   xenbr0          8000.feffffffffff       no              vif1.0
> 
> 
> Since I am new to xen I assume I miss something crucial here. Or beta6
> has a bug? Any hint for enlightment is welcome.
> 
> Thanks,
I received one private reply recommending not using SuSE. However, I am
kind of sceptical here since Kurt Garloff from SuSE explicitely writes
Xen RPM''s for SuSE.

However, I wrote him an email explaining the problem and to share the
gained knowledge I''ll translate his German reply here:


"To make everything work with SuSE you have to set up your network as
follows:
1) choose the ''classic'' way of setting up network (no
''NetworkManager''
as offered by Yast)
2) put STARTMODE of ifplugd to ''onboot'' (defaults to
''on connect'')
3) turn off SuSEfirewall2 or configure it properly
4) enable ip_forward (either by using Yast or sysctl.conf)"

In my case 2, 3, 4 and a reboot fixed it. I have full network of Dom0
and DomU now. I''ll put Kurt Garloffs hints into the wiki on

   http://en.opensuse.org/Installing_Xen3


Thanks Kurt!

-- 

 Stephan A. Rickauer

 -----------------------------------------------------------
 Institut für Neuroinformatik          Tel: +41 44 635 30 50
 Universität / ETH Zürich              Sek: +41 44 635 30 52
 Winterthurerstrasse 190               Fax: +41 44 635 30 53
 CH-8057 Zürich                        Web:  www.ini.ethz.ch

 RSA public key: https://www.ini.ethz.ch/~stephan/pubkey.asc
 -----------------------------------------------------------



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Xen-users mailing list
Xen-users@lists.xensource.com
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Stephan,

On Thu, Mar 09, 2006 at 10:55:48AM +0100, Stephan A. Rickauer wrote:
[...]
> > Since I am new to xen I assume I miss something crucial here. Or beta6
> > has a bug? Any hint for enlightment is welcome.
> 
> I received one private reply recommending not using SuSE. However, I am
> kind of sceptical here since Kurt Garloff from SuSE explicitely writes
> Xen RPM''s for SuSE.
> 
> However, I wrote him an email explaining the problem and to share the
> gained knowledge I''ll translate his German reply here:
> 
> 
> "To make everything work with SuSE you have to set up your network as
> follows:
> 1) choose the ''classic'' way of setting up network (no
''NetworkManager''
> as offered by Yast)
> 2) put STARTMODE of ifplugd to ''onboot'' (defaults to
''on connect'')
in /etc/sysconfig/network/ifcfg-eth*
> 3) turn off SuSEfirewall2 or configure it properly
which means enabling FW_ROUTE, listing the xenbr0 interface in
FW_DEV_xxx and allowing FW_ALLOW_CLASS_ROUTING. Watch the kernel
netfilter log messages if things go wrong. Be aware that martians
are not always indicating a problem.
> 4) enable ip_forward (either by using Yast or sysctl.conf)"
IP_FORWARD="yes" in /etc/sysconfig/sysctl, which sets the
/proc/sys/net/ipv4/ip_forward kernel sysctl parameter.
> In my case 2, 3, 4 and a reboot fixed it. I have full network of Dom0
> and DomU now. I''ll put Kurt Garloffs hints into the wiki on
> 
>    http://en.opensuse.org/Installing_Xen3
I''m really glad my hints helped you to get Xen3 working on the 10.1
betas.

Thanks for documenting this in the Wiki; I should have done that, but
there''s a limited number of things I can get done, so I really
appreciate you going forward with it. I''m also glad that you pointed
out that this issue hits many people; I''m trying to follow xen-devel,
but I''m not able to regularly read xen-users. If any more such issues 
pop up in the future, please point them out to me.

Another alternative is using routing in xen-config.sxp (and masquerading
or proxy-arp) rather than bridging. It''s somewhat less complicated, but
is less straightforward if you want to do VM migration.

One more remark:
The network-bridge script renames interfaces (eth->peth0, veth0->eth0),
which fails in case the device is in use. The script does ifdown
them, but this is not effective if ifplugd or NetworkManager run.
I''m currently investigating the best way to solve this. One possibility
would be to make sure ifdown is effective for these cases as well.
The other option (which I currently believe is more promising) would
be to create another boot script that runs early and does the remaining
prior to the network scripts run for the first time.

So I hope the restriction to not use NetworkManager nor ifplugd will
go away soon.

So we''ll make sure there''s less (ideally no) tweaking required
in
future betas.

Best,
-- 
Kurt Garloff, Head Architect Linux, Novell Inc.


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