Cogent IPv6

George Bonser gbonser at
Thu Jun 9 19:35:13 UTC 2011

> Some networks prefer a uniform numbering scheme. /112 allows for
> reasonable addressing needs on a circuit. In addition, while Ethernet
> is
> often used in a point-to-point access circuit, such layouts may change
> and renumbering would be annoying.
> Finally, having chunks 4-7 define the circuit and chunk 8 provide the
> circuit addressing makes it more human readable and is prone to less
> mistakes by those who suck at math.
> Jack

I actually see that as a pretty good compromise.  You could have all of
your point-to-points at a pop in the same /64, you can give them all ::1
and ::2 addressing, and the addressing scheme supports both
point-to-point and point-to-multipoint topologies. A customer with
multiple locations in a region could run a circuit from each location
and they could possibly all be in the same /112.  If they want to
multihome to you, they run similar links to a different pop in a
different /112 in a different /64 that is part of that pop's /48.  And
the numbering is consistent at the user end. The ::2 site or ::3 site
would be the ::2 site or ::3 from both pops with a different prefix.
Seems reasonable to me.

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