[AusNOG] IPv6

[Karl Auer]

On Fri, 2015-03-27 at 00:09 +0000, Mark ZZZ Smith wrote:
> To make Mark's point slightly clearer, native IPv4 has been preferred
> over tunnelled IPv6 for many years

Only if the tunnel can be identified via the prefix - like 6to4, Teredo
etc. If you use a TSP tunnel broker, you won't get this effect. Not sure
about HE, SIXXS etc, but I would imagine probably not with them either.
Unless I've failed to keep up and the kernel now actually inspects the
endpoint to see if it is a tunnel device.

>  default, tunnelled IPv6 is commonly not going to be as good as native
> IPv4.

The margin, with a local tunnel endpoint, can be surprisingly slim. And
because a lot of people use different IPv6 paths to IPv4 paths, you can
even sometimes *win* with tunnelled IPv6. That was true for me for a
while when my tunnel broker was doing IPv6 over NTT, while IPv4 was
going via <mumble>. Native now and there is no discernable difference.

> / Under Linux, the address selection preferences can be changed using gai.conf(5).

True, but if you muck about with gai.conf, read this first:

http://into6.com.au/?p=288

It may save you some time. Unless (again) the world has changed since I
wrote it. I suppose I should check :-)

Regards, K.

-- 
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Karl Auer                                          tel  +61-2-64957435
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