Deploying IPv6 in an ISP network [ was: Best Source for ARIN Region /24 ]

Tue Jan 12 18:44:06 UTC 2016

On 12 January 2016 at 19:03, Owen DeLong <owen at delong.com> wrote:

> > As an alternative to the plan that Owen describes, I can offer the way we
> > did it: Our IPv6 address plan is tied to our IPv4 addressing, such that
> > there is a mapping from IPv4 address to IPv6 /48 prefix. That way we do
> not
> > need to allocate IPv6 as such.
>
> How do you expect that to work out when you have customers without IPv4
> addresses
> or once you start having to share IPv4 addresses among customers?
>
>
I fear I will be retired before the first happens. As to the second, even
with CGN they will have an internal IPv4 that can be used for the mapping.

Please also take notice that there is nothing that prevents you from
reversing the mapping: assign /48 to customers and then calculate the IPv4
from that. The point here is just that you do not really need to do the
work twice.

The limitation of the system is that it requires a dense scheme for
allocating /48 to customers. Unfortunately that is already a requirement in
RIPE land, so it does not add something new.

> Your address plan ties your future to your legacy technology that you
> should
> be looking forward to deprecating and places limitations on your future
> addressing that are coupled to the shortcomings of the legacy addressing
> capabilities.
>
>
I would say it saves you from doing a lot of work. It will be a long time
before you can skip the IPv4 part entirely and just do IPv6. The exception
being if you use certain transition technologies that tunnels IPv4 on top
of an IPv6 only network, in which case I would probably do something
different (or maybe not). My scheme works for our network, which uses L3VPN
and MPLS.

> I encourage my competitors to attempt this strategy.
>

I do not believe we have ever been competitors...

Regards,

Baldur