Re: Ipv6 and preferred_lft

On Mon, Oct 14, 2013 at 11:09:14AM +0200, Mark Schouten wrote:
> On 10/13/2013 03:02 PM, Ryan O'Hara wrote:
> > A few months ago I investigated this problem and made the suggestion
> > to use the 'bindto' parameter in the health check. I have a couple
> > concerns about the proposed fix, so today I went back and attempted to
> > recreate this problem. I was unable to do so. Exactly what steps are
> > being taken to see the behavior where health checks to IPv6 addresses
> > use the wrong source address? A quick setup on my development machines
> > worked as expected. Please advise.
> 
> Please explain your concerns with this patch, as I can not think of a
> single one...

First, the setting is not optional. It should be. This problem, which
I am unable to recreate, only exists with you are using keepalived
with both 'vrrp' and 'check' enabled. I understand this a common case,
but not everybody uses keepalived's IPVS capabilities. I'm not sure
that changing this behavior will not cause problems for other valid
configurations.

Also, the DaD optimization is better addressed using the sysctl
settings:

net.ipv6.conf.*.optimistic_dad

Which can be set for all interfaces or per interface.

Ryan


------------------------------------------------------------------------------
October Webinars: Code for Performance
Free Intel webinars can help you accelerate application performance.
Explore tips for MPI, OpenMP, advanced profiling, and more. Get the most from 
the latest Intel processors and coprocessors. See abstracts and register >
http://pubads.g.doubleclick.net/gampad/clk?id=60134071&iu=/4140/ostg.clktrk