Re: [PATCH RFC 00/24] IPVS: Add first IPv6 support to IPVS

To: "Sven Wegener" <sven.wegener@xxxxxxxxxxx>
Subject: Re: [PATCH RFC 00/24] IPVS: Add first IPv6 support to IPVS
Cc: "Graeme Fowler" <graeme@xxxxxxxxxxx>, "Simon Horman" <horms@xxxxxxxxxxxx>, netdev@xxxxxxxxxxxxxxx, lvs-devel@xxxxxxxxxxxxxxx, kaber@xxxxxxxxx, vbusam@xxxxxxxxxx
From: "Julius Volz" <juliusv@xxxxxxxxxx>
Date: Fri, 22 Aug 2008 14:14:11 +0200
On Fri, Aug 22, 2008 at 1:23 PM, Sven Wegener <sven.wegener@xxxxxxxxxxx> wrote:
>> He :) Imagine an old kernel on the backup receiving new messages and
>> not understanding them. How could we at least handle that situation
>> gracefully (without totally confusing the older kernel)? We'd need to
>> do it in a way that old features are still communicated in the same
>> way. E.g., v4-only connection syncs still use the same message format,
>> but once you use v6 entries, an unused flag or the 'reserved' field in
>> ip_vs_sync_conn is used. A v6 message would still confuse an older
>> kernel then, but a user would already notice that ipvsadm can't
>> configure the v6 services on the older kernel, so that's not too bad.
> If that's a problem, we can easily change the communication port and even
> completely redesign the protocol this way, without having old kernels
> getting confused about the data they get. We might lose the ability to
> sync between different versions, but in the end this is just the
> connection synchronziation and both systems should be running the same
> version. We could also keep the old communication port for some time, if
> that's really needed.

Yes, starting from scratch on another port sounds like a good idea.
Losing sync ability totally isn't as bad as confusing an older kernel
with new messages, so I hope it's not necessary to keep the old
baggage around?

Is there enough motivation for doing this though before having a
cleaned-up minimal v6 version without the sync daemon? This is where
I'm currently a bit stuck with... any help is appreciated :)


Google Switzerland GmbH
To unsubscribe from this list: send the line "unsubscribe lvs-devel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at

<Prev in Thread] Current Thread [Next in Thread>