________________________________________________________________________ prop-048-v001: IPv6 ULA-central ________________________________________________________________________ Author: Jordi Palet Martinez, Consulintel Version: 1 Date: 14 April 2007 Introduction ------------ This policy is intended to allow the assignment of IPv6 blocks within the so-called "Centrally Assigned Unique Local IPv6 Unicast Addresses" (see http://tools.ietf.org/html/draft-ietf-ipv6-ula-central-01) 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). Summary of current problem -------------------------- 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), etc. Situation in other RIRs ----------------------- This policy proposal has already been submitted to the other regions. Some of them have not yet published it at the time of submission to APNIC. Proposal details ---------------- Definition of ULA-central ULA-central refers to the Centrally Assigned Unique Local IPv6 Unicast Addresses as described in the IETF document "ietf-ipv6-ula-central" (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. 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 (RFC 4193) 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 portable assignments) and consequently must be filtered. Advantages and disadvantages of adopting the proposed policy ------------------------------------------------------------ a. Advantages 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), etc. The "Micro-allocations for Internal Infrastructure" document from ARIN (policy proposal 2006-2, authored by Jason Schiller et al., available at http://www.arin.net/policy/proposals/2006_2.html), describes the need of this kind of additional block for purposes BGP Re-Convergence, Internal Infrastructure Security and why locally assigned ULAs (RFC 4193) addresses are not appropriate. Such policy proposal was accepted through the policy development process and it is already part of the ARIN Number Resource Policy Manual. 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. Disadvantages 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 RFC 4193. From the same document, it is clearly documented the reasons why this prefix will not be useful as IPv6 portable assignments and will be filtered out in the global Internet. Effect on APNIC members ----------------------- None expected. Effect on NIRs -------------- They may need to adopt an equivalent proposal, or, as the number of assignations will be low, rely directly on the same system which may become implemented by APNIC. Acknowledgments --------------- 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 work.