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[AfriNIC-rpd] New policy proposal: IPv6 ULA-central

Sun Apr 1 19:39:50 UTC 2007

Hi all,

This is a new policy proposal, just to make sure to avoid any confusion: It
is NOT related with the IPv6 PI.

As discussed with the NRO, I'm submitting this proposal to all the RIRs.

Please, read the text and make sure to ask any questions that you may have.
This is a completely new topic, and I fully understand that may require lot
of explanations for those that didn't followed the development of ULA at
IETF. I strongly suggest to read RFC4193
( and

This time, because the timing of the different regions meetings, AfriNIC has
the opportunity to be the leader if we are able to reach consensus on this

Thanks in advance for your inputs !


  Policy Proposal Name:   IPv6 ULA-central
  Author:     Jordi Palet Martinez, Consulintel
  Proposal Version:   1.0
  Submission Date:   1st April 2007
  Current Status :   Discussion Phase - Open for Discussion
  Suggested WG for Discussion and Publication:   Address Policy
  Proposal Type:   New
  Policy Term:   Permanent

Summary of Proposal:
This policy is intended to allow the assignment of IPv6 blocks within the
so-called ³Centrally Assigned Unique Local IPv6 Unicast Addresses² (see to organizations
or individuals requiring it. These addresses are globally unique and
intended for local communications, usually within a site or set of them and
are not expected to be routable on the global Internet. Prefix FC00::/7 is
already reserved by IANA for ULA (bit 8 determines if locally or centrally
assigned, so ULA or ULA-central).

Draft Policy Text: 
New text, possibly as section 2.6:
2.6. ULA-central
ULA-central refers to the Centrally Assigned Unique Local IPv6 Unicast
Addresses as described in the IETF document ³ietf-ipv6-ula-central²
(whatever version is the most recent, as an Internet Draft, RFC or STD). The
ULA-central block is within the prefix FC00::/7, with bit 8 set to 0.
New text, possibly as section 7:
7. Assignment of ULA-central blocks
Any organization or individual requiring a /48 from the ULA-central block
will be able to get it assigned, once the relevant contract is executed and
related membership fees are paid (to be determined by the board).
Note that in most of the cases, locally assigned ULA addresses (RFC4193) are
preferred, and it is only expected that large managed sites will prefer
central assignments. It is also important to reinforce that the ULA prefix
(FC00::/7) it is not routable in the global Internet (i.e., not designed to
be used as IPv6 PI) and consequently must be filtered.

a. Arguments Supporting the Proposal

In some situations, especially large sites in organizations, which already
may have Global Unicast IPv6 blocks, may require an additional block for
their internal infrastructure.
This additional block can be used for a number of purposes, such as VPNs,
site-to-site communications, avoiding dual/multiple faced DNSs, support for
applications which are sensitive to long convergence times (such as VoIP),
The ³Micro-allocations for Internal Infrastructure² document from ARIN
(policy proposal 2006-2, authored by Jason Schiller et al., available at, document describes the
need of this kind of additional block for purposes BGP Re-Convergence,
Internal Infrastructure Security and why locally assigned ULAs (RFC4193)
addresses are not appropriate.
The usage of Global Unicast IPv6 blocks for this type of purposes must be
considered as wasteful, especially when there is already an IANA reserved
prefix (FC00::/7) for doing so.

b. Arguments Opposing the Proposal

None foreseen. However, it should be clear that the original scope of
ULA-central is for large managed sites and all other cases should use
locally assigned ULAs as per RFC4193. From the same document, it is clearly
documented the reasons why this prefix will not be useful as IPv6 PI and
will be filtered out in the global Internet.

I would like to acknowledge to the authors of the ULA-central work at IETF,
Bob Hinden and Brian Haberman and all those who also contributed to that

The IPv6 Portal:

Bye 6Bone. Hi, IPv6 !

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