Is CONFIG_IP_VS_IPV6 still/really dangerous?

Is CONFIG_IP_VS_IPV6 still/really dangerous?

[Ferenc Wagner]

Hi,

In commit fab0de02fb0da83b90cec7fce4294747d86d5c6f CONFIG_IP_VS_IPV6 is
described as:

    Add IPv6 support to IPVS. This is incomplete and might be dangerous.

I agree its implementation is incomplete.  But I wonder if it's really
dangerous in the sense that generic distribution kernels shouldn't
enable it, because it can break unrelated (eg. IPv4 IPVS) functionality.

What does that warning mean today?  Isn't it out of date?
-- 
Thanks,
Feri.

Re: Is CONFIG_IP_VS_IPV6 still/really dangerous?

[Julius Volz]

Hi Ferenc,

On Fri, Jun 4, 2010 at 3:56 PM, Ferenc Wagner <wferi@niif.hu> wrote:
> Hi,
>
> In commit fab0de02fb0da83b90cec7fce4294747d86d5c6f CONFIG_IP_VS_IPV6 is
> described as:
>
>    Add IPv6 support to IPVS. This is incomplete and might be dangerous.
>
> I agree its implementation is incomplete.  But I wonder if it's really
> dangerous in the sense that generic distribution kernels shouldn't
> enable it, because it can break unrelated (eg. IPv4 IPVS) functionality.
>
> What does that warning mean today?  Isn't it out of date?

I wrote the IPv6 support back in the day, but never used it
large-scale. Rob Gallagher from HEAnet was doing some bigger
experiments with it, but I'm not sure how far it went. CCing him.

There are probably some other people out there that have tested it
extensively. Maybe try the lvs-users and lvs-devel mailing lists?

http://www.linuxvirtualserver.org/mailing.html

Julius

-- 
Julius Volz - Site Reliability Engineer
Google Switzerland GmbH - Identification No.: CH-020.4.028.116-1

Re: Is CONFIG_IP_VS_IPV6 still/really dangerous?

[Ferenc Wagner]

Julius Volz <juliusv@google.com> writes:

> On Fri, Jun 4, 2010 at 3:56 PM, Ferenc Wagner <wferi@niif.hu> wrote:
>
>> In commit fab0de02fb0da83b90cec7fce4294747d86d5c6f CONFIG_IP_VS_IPV6 is
>> described as:
>>
>>    Add IPv6 support to IPVS. This is incomplete and might be dangerous.
>>
>> I agree its implementation is incomplete.  But I wonder if it's really
>> dangerous in the sense that generic distribution kernels shouldn't
>> enable it, because it can break unrelated (eg. IPv4 IPVS) functionality.
>>
>> What does that warning mean today?  Isn't it out of date?
>
> I wrote the IPv6 support back in the day, but never used it
> large-scale. Rob Gallagher from HEAnet was doing some bigger
> experiments with it, but I'm not sure how far it went. CCing him.
>
> There are probably some other people out there that have tested it
> extensively. Maybe try the lvs-users and lvs-devel mailing lists?

Sounds like a good idea!  So:

Dear lvs-users,

did you experience any breakage as a result of switching on
CONFIG_IP_VS_IPV6?  I mean apart from it having incomplete
functionality.  The gist of the question is whether this option
is suitable for generic distro kernels or not, cf. above.
-- 
Thanks for your time,
Feri.