[arin-ppml] IPv6 End-User Initial Assignment Policy (or: Please don't me make do ULA + NAT66)

William Herrin bill at herrin.us
Wed Feb 18 11:43:45 EST 2015

On Wed, Feb 18, 2015 at 11:11 AM, Gary T. Giesen <ggiesen at giesen.me> wrote:
> Imagine a scenario where a company has 10 VPN tunnels to suppliers,
> partners, etc. Imagine it takes 2 months per tunnel to renumber by the time
> you've gone through the change control process on both sides, etc. That
> could be nearly two years of fairly concerted effort, and none of those are
> at all unrealistic numbers.

Hi Gary,

Renumbering is HARD. Renumbering is EXPENSIVE. Few fools still claim otherwise.

On the other hand routing slots are also expensive and fairly
distributing the $10k/year systemic cost guesstimate of an IPv6
routing slot to the 40k or so organizations who are collectively
compelled to spend it has proven to be an intractable problem. I
worked up a BGP cost estimate half a decade ago; the numbers are out
of date but you may still find it informative.

The renumbering cost is not a good enough reason to increase the IPv6
table size. This is pointed out in NRPM 6.3.8: "In IPv6 address
policy, the goal of aggregation is considered to be the most
important." This means aggregation with your ISP's address space where
technically feasible.

Frankly, the solution to your problem is: buy a second ISP link at
your core site that the other sites aggregate to. Even if it's just a
backup link based on commodity DSL, cable or satellite plus a tunnel
out to a data center-located BGP speaker.

Having multihomed, aggregation with your ISP is no longer technically
feasible. This has been proven over and over again. That's why it's
one of the criteria that establishes justification for IPv6 direct
assignments. Multihoming eliminates your business risk for not being
able to get IPv6 addresses. And such a simple backup link is for sure
less expensive than the renumbering cost.

And as an added bonus it makes your network more reliable. ;)

Bill Herrin

William Herrin ................ herrin at dirtside.com  bill at herrin.us
Owner, Dirtside Systems ......... Web: <http://www.dirtside.com/>

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