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

Tue Jan 12 15:08:59 UTC 2016

Do you seek information on how to plan subnetting or on more technical
issues like how to dual stack your network? In the later case, you would
need to tell more about your network. Eg. if you have a MPLS network (like
we do) and you have your internet in a L3VPN enabling IPv6 is really easy
and has almost no impact on the network.

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.

The mapping is a database with IPv4 /24 as key and IPv6 /40 as value.
Example:

85.204.120.0/24 maps to 2a00:7660:500::/40.

Take the user with the IPv4 address 85.204.120.12. This address maps to
2a00:7660:50b::/48. Note that 12 is "0b" in hexadecimal.

We are an eyeball network where most users have only one single IPv4
address. We assign the IPv4 addresses statically (never changes). A few
users bought extra IPv4 address and that creates a hole in our address
plan, but we do not care. Officially the extra /48 is not assigned to the
user, because that would be against the rules.

Our address plan creates a very efficient allocation scheme, that is not
strictly needed as you have the more loose ARIN rules (we are in RIPE).

Regards,

Baldur