IPv6 Source Address Selection on Mac OS X Lion

Gert Doering gert at space.net
Fri Dec 16 19:05:23 CET 2011


On Thu, Dec 15, 2011 at 09:31:42AM -0800, Dan Wing wrote:
> It depends on your definition of "better".  If your definition is
> "prefer IPv6", you are right that OSX Lion's algorithm fails.  If
> your definition is "connect to whichever is fastest", OSX Lion's
> algorithm wins.

"consistent behaviour".  And this is where Lion fails, because it
flip-flops back and forth between protocols even if nothing changes
in the network.

> Right now, on effectively every network in the world, there is 
> no user-noticable advantage to using IPv6 over IPv4.  Users don't
> care if their connection to Google/Facebook/Yahoo is IPv6 or IPv4,
> and nothing different happens to the user -- they don't get 
> additional cows for their games, they don't get IPv6 coupons for 
> the pizza place down the road.

Operators care, because for debugging, "I'll do IPv6 today and IPv4
tomorrow, and there is no way to influence preference" is a nightmare.

Gert Doering
        -- NetMaster
have you enabled IPv6 on something today...?

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