IPv6 Server Load Balancing - DSR

Leland Vandervort leland at taranta.discpro.org
Thu Aug 12 12:34:18 CDT 2010


Well, Frankly our "culture" is very much open source, so if we can find something along those lines, then it would be preferred.  (Hence looking at OpenSolaris and ILB). -- having said that, we do have both F5 and Foundry kit here, but it's all pre-IPv6 so doesn't have the support built in.  Not really looking to replace what is in existence already for IPv4 with something new to do both, so really that reinforces the open-source avenue really.

I think the biggest problem is really the DSR aspect for IPv6, since the OS/ILB solution works perfectly in NAT mode, and DSR works perfectly with IPv4 on this solution.  So either I'm missing something critical on the "real" server configuration, or ILB's implementation of DSR for IPv6 doesn't really work.  The "virtual" IP is bound to loopback on the real servers, exactly the same was as for IPv4.  So other than something quirky going on with ND, or simply ILB not correctly rewriting the L2 frame, or there's something else more sinister afoot that I'm unable to put my finger on.

Back to the drawing board... :)


Thanks,

Leland





On 12 Aug 2010, at 19:23, William Cooper wrote:

> I know there have been quite a few responses for both h/w and s/w
> solutions, it's not clear
> which your preference is of the two. I know there are various h/w
> vendors that offer a s/w
> solution (mostly in conjunction with some form of virtualization
> environment), such as A10.
> 
> I've been testing A10 for a while now, and they seem very keen on
> developing parity between
> v4 and v6 feature sets / performance.
> 
> DSR is more or less a L2 trick that plays on some inherent weaknesses
> and constraints
> that are present with v4 local address resolution (don't mean to
> preach to the chior); I think
> most responses here have touched on the primary challenges of DSR with
> v6. I'll be exploring
> DSR with dual stack v4/6 in the near future, I'll let you know how
> that turns out.
> 
> Hmm... not sure how this helped.
> 
> Regards,
> 
> -Tony
> 
> On Thu, Aug 12, 2010 at 12:40 PM, Leland Vandervort
> <leland at taranta.discpro.org> wrote:
>> Hi Owen,
>> 
>> The DSR address is indeed on a loopback in our case.
>> 
>> lo        Link encap:Local Loopback
>>          inet6 addr: ::1/128 Scope:Host
>>          inet6 addr: xxxx:xxxx:x:xxxx::xx/128 Scope:Global
>> 
>> 
>> 
>> The mystery continues...
>> 
>> 
>> Leland
>> 
>> 
>> On 12 Aug 2010, at 18:28, Owen DeLong wrote:
>> 
>>> 
>>> On Aug 12, 2010, at 6:19 AM, Xavier Beaudouin wrote:
>>> 
>>>> Hi Leland,
>>>> 
>>>> Le 12 août 2010 à 15:11, Leland Vandervort a écrit :
>>>> 
>>>>> OpenSolaris ILB is open solution ;)
>>>>> 
>>>>> but yea, that's what we've started looking at -- hence LVM / HAProxy as well.. (though LVM is IPv4 only, and HAProxy is NAT only for IPv6)
>>>>> 
>>>>> does relayd support UDP as well as TCP or is it layer7 only like HAProxy ?
>>>> 
>>>> It does everything... :) L2 -> L7...
>>>> 
>>>>> In the case of ILB, I'm not convinced that it's a problem with the LB itself, but rather the idiosyncrasies of ND in IPv6 that is causing the problem.. but I may be wrong... at any rate, something's amiss ...
>>>> 
>>>> Maybe on some setup you should desactivate ND...
>>>> 
>>>> Xavier
>>> 
>>> If you're putting the DSR address on an interface other than loopback, you probably need to turn of DAD on the interface with the DSR address otherwise DAD
>>> will shut down that address on the interface when it sees other servers with the same address. Sometimes it will shut down all but one, sometimes it will
>>> shut down all.
>>> 
>>> 
>>> Owen
>> 
>> 
>> 





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