Test your connectivity for World IPv6 Day

Tore Anderson tore.anderson at redpill-linpro.com
Tue Jun 7 00:20:00 CEST 2011

* Rémi Després

> Fixing known problems of PMTU discovery before trying to do better
> than 1280 is an alternative that I recommend, especially for servers
> that have important contents to deliver.

It's quite hard to discover the blackholes (and by extension fix them)
if you're defaulting to 1280. And if 1280 becomes the de-facto standard,
the blackholes are free to proliferate. That said, it might be a
sensible way to minimise the set of potential problems when first
publishing AAAAs.

For what it's worth we changed www.vg.no from 1280 to 1500 a couple of
months ago. No complaints so far. In any case, the few users that have
HE/SixXS/etc. tunnels can take care of themselves. If it breaks, they
get to keep both parts.

For real deployments, on the other hand ... well, I'm hoping no serious
ISP or content provider will willingly put their end users or web sites
behind MTU-impaired links or tunnels. Recipe for disaster if you ask me.

Tore Anderson
Redpill Linpro AS - http://www.redpill-linpro.com/
Tel: +47 21 54 41 27

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