[Debian] IPv6 trouble with Lenny kernel

[Ola Lundqvist]

Hi Benoit

Sorry for the long delay, but I do not check this list so often.
In the future it is better to submit bug reports. :-)

On Wed, May 27, 2009 at 06:02:40PM +0200, Benoit Branciard wrote:
> Hi all,
>
> I'm running into trouble while trying to get IPv6 running inside VEs  
> with Lenny OpenVZ kernel.
>
> Our production HW nodes are running:
> - Debian Etch AMD64
> - linux-image-2.6.18-14-fza-amd64 028stab056.1dso1 (Debian-Systs) kernel
> - vzctl 3.0.23-1dso1~etch0
> - IPv6-enabled Etch and Lenny VEs with venet devices
>
> This setup works happily for both IPv4 and IPv6 protocols.
>
> Now I upgraded one test HN to Lenny, and installed  
> linux-image-2.6.26-2-openvz-amd64 2.6.26-15lenny2 (Debian-provided)  
> kernel, all other things remaining the same (most notably, no VE were  
> modified nor upgraded).
>
> This resulted in a sort or ARP-related problem:

Ok.

> - during a short time after HN boot (three minutes or so), VEs have a  
> working IPv6: HN, local network and non-local hosts can be successfully  
> accessed.
>
> - After this delay, only the HN address can be reached from inside VEs,  
> all other IPv6 addresses become unreachable.
>
> This problem does not affect IPv4, and does not affect the IPv6  
> capability of the hardware node itself (all IPv6 addresses can be pinged  
> from the hardware node).

Interesting.

> Rebooting the HN on the linux-image-2.6.18-14-fza-amd64 kernel (while  
> maintaining the Lenny binaries) restores total IPv6 functionality, so  
> the problem seems kernel-related.
>
> This problem resembles an older bug related to "ip" command parsing in  
> /usr/lib/vzctl/scripts/vps-functions (see:  
> http://openvz.org/pipermail/users/2008-January/001658.html), but is not  
> the same. Running the "vz_get_neighbour_devs" function manually returns  
> the correct value here:
>
> . /etc/vz/vz.conf ; . /usr/lib/vzctl/scripts/vps-functions ; vzgetnetdev  
> ; vz_get_neighbour_devs MY:IPV6:ADD:RESS
>
> displays the expected HN public interface.
>
> Any idea on how to resolve this ?

Can I ask you to write a bug report against the kernel version you are
using? If you do not know how to do that, I can do that for you.

Best regards,

// Ola

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-- 
 --------------------- Ola Lundqvist ---------------------------
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