google ipv6 routes via cogent

Dennis Bohn bohn at
Fri Mar 3 02:01:08 UTC 2017

Interesting question whether 2000::/3 or ::/0 is the better default route.
>From what I can tell (as OP indicated) most are using ::/0. (I should
probably add for those who have not been running V6 for long that for the
forseeble future 2000::/3 is the extent of the V6 allocation, the rest
being held back for future use. Which is why that could be a default.) Is
there any case where 2000::/3 would hurt one? One person mentioned
something like 64:ff9b::/96, which per,
is the v4 to v6 translator net. Does anyone actually use that?

Dennis Bohn
Manager of Network and Systems (ret)
Adelphi University
bohn at

On Thu, Mar 2, 2017 at 12:20 PM, Baldur Norddahl <baldur.norddahl at>

> Shouldn't that be 2000::/3 ?
> Den 2. mar. 2017 17.06 skrev "Aaron Gould" <aaron1 at>:
> Correction...  ::/0 is what I learn from those 3     :)

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