I-Context

On June 13, 2007, the AfriNIC community adopted after long debates, the policy for IPv6 PI assignments for end-sites (http://www.afrinic.net/docs/policies/afpol-v6200701.htm).

 The implementation of the policy started on 12 July 2007 as announced by the mail from the hostmaster sent to the following lists: rpd@afrinic.net, announce@afrinic.net, afnog@afnog.org, afripv6-discuss@afrinic.net, global-v6@apnic.net, ppml@arin.net, address-policy-wg@ripe.net. The same day, the message was transferred to nanog@nanog.org and on politicas@lacnic.net. (https://lists.afrinic.net/pipermail/rpd/2007/000776.html)

 In a message on August 14, 2007, Mark J Elkins informed the community of the difficulties he was facing with the routing of the PI prefix 2001:43f8:30::/48. (https://lists.afrinic.net/pipermail/afripv6-discuss/2007/000129.html)

 The prefix recorded only a visibility of 80% while PA allocations, i-e the /32 of AfriNIC showed a visibility bordering the 100%. (http://www.sixxs.net/tools/grh/dfp/all/?country=za)

AIRRS project team has decided to make some investigations:

1- To identify the causes of the problems
2- To identify possible solutions
 
II-Background

II-1 Situation of the allocations of IPv6 addresses in the five regions

 If all the five regions allocate IPv6 prefixes to LIRs with a minimum of /32, the situation varies according to the region with regard to the portable assignments.
          
AFRINIC

 PI assignments are possible in the AfriNIC region since the adoption of the policy on  IPv6 Provider Independent (PI) Assignment for End-Sites"
 (http://www.afrinic.net/docs/policies/afpol-v6200701.htm)
      
 End-Site includes End-Users  who already have or qualify to get IPv4 PI addresses and critical Infrastructure providers such as TLD, root server operators and public Internet eXchange Points (IXP's)

The intial provider independent assignment size to an end-site should be a /48, or a shorter prefix if the end-site can justify it.

APNIC

Three portable assignments cases are authorized in the Asia Pacific region:

 
- Organizations multihomed or projected to become it within three month are qualified to receive a portable assignment.
The minimum assignment made under these terms is /48.

- The following critical infrastructure networks, if operating in the Asia Pacific region, are eligible to receive a portable assignment:

The maximum assignment made under these terms is /32 per operator.

- Internet Exchange Points are eligible to receive a portable assignment from APNIC to be used exclusively to connect the IXP participant devices to the Exchange Point.
The minimum assignment made under these terms is /48.
http://www.apnic.int/services/portable-assign/eligibility-portable.html

ARIN

In ARIN region, direct assignments to the end-users are possible. The minimum size of the assignment is /48. Organizations requesting larger assignment must provide documentation justifying the need for additional subnets.
(http://www.arin.net/policy/nrpm.html)

 Micro-allocations are also made for Internet operators of critical infrastructures, like the public IXPs, core DNS service providers (e.g. ICANN-sanctioned root, gTLD, and ccTLD operators) as well as the RIRs and IANA.
 
These allocations will be no longer than a /48. Multiple allocations may be granted in certain situations.

The micro-allocations are available at: www.arin.net/reference/micro_allocations.html  

LACNIC

LACNIC makes micro-allocations in case of projects and network infrastructure that are key or critical for the operation and development of IPv6 within the region, such as IXPs (Internet Exchange Points), NAPs (Network Access Points), RIRs (Regional Internet Registries), DNS ccTLD providers, among others.

These allocations shall be made in blocks smaller than or equal a /32 but always greater than or equal to a /48.

RIPE NCC

In RIPE region, the portable assignments are possible for root servers operators operating in the region on the minimum allocated to LIRs at the moment, which is /32 (http://www.ripe.net/ripe/docs/ripe-233.html)

Certain operators of TLD (ccTLD and gTLD) can be qualified to receive assignments for DNS Anycast service. The size of the allocated prefix is /48.

The prefix will be assigned by the RIPE NCC directly to the TLD, upon a request submitted via an existing LIR and will be registered with a status of 'ASSIGNED ANYCAST' in the RIPE Database and must be returned to the RIPE NCC if not in use for anycast DNS any longer.
http://www.ripe.net/ripe/docs/ripe-421.html

IXPs are qualified to receive assignments. If the requesting organization is confident that it will never need more than a single network then a /64 will be assigned. Otherwise, a /48 will be assigned. http://www.ripe.net/ripe/docs/ripe-256.html


II-2 Prefixes and minimum allocation and assignment size per region

The prefixes list and minimum of allocation and assignment size can be found for the five regions at the following places:

http://www.afrinic.net/Registration/resources.htm
http://www.apnic.net/db/min-alloc.html
http://www.arin.net/reference/ip_blocks.html
http://lacnic.net/en/registro/index.html
http://www.ripe.net/ripe/docs/ripe-415.html

III-Course of the investigations

In order to carry out the investigations, the AIRRS (African Internet resources and
Routing Statistics) project team requested a temporary  PI assignment of a /48 for some testing purpose. The prefix assigned by AfriNIC is the 2001:43f8:40::/48.
                
 Tests environment uses AS33764 which has IPv6 transit from AS1280 and AS2905. The prefix has been announced and was accepted by both upstreams.

 AS1280 passed the prefix to its peers and this gave a visibility of 81% on the scale of Ghost Route Hunter's IPv6 DFP visibility. (http://www.sixxs.net/tools/grh/dfp/afrinic/)
           
 AS12702 V6 transit provider of AS2905 accept the prefix but does not pass it to its peers for routes filtering reasons.

 Our exchanges with the NOC of AS2905 revealed the followings:

1- Only /48 from the ARIN micro-allocations block 2001:500::/30 are passed to peers by AS12702 and AS701.

2- These ASes  filter IPv6 routes on the /32 boundary.

3- They are not adjusting filters for PI /48 as announced by RIRs, because on the global IPv6 view, IPv6 PI isn't defined in any RFC.

4- Their IPv6 routing filters decision is to not support PI assignment approach until the IPv6 multihoming and PI topic is somehow standardized.

 The visibility recorded by /48 from ARIN micro-allocations from 2001:500::/30 shows the impact of these types of routes filtering on the routing. (http://www.sixxs.net/tools/grh/dfp/arin/)

IV-Findings

On the basis of our experiment, we present the following findings for consideration by the AfriNIC community:

1- The concept of IPv6 portable assignment is not yet widely accepted by the global community,

2- Certain operators filter IPv6 prefixes on the /32 boundary and are not adjusting filters to accommodate PI  assignments as  announced by the RIRs

3- The concept of IPv6 micro-allocation for critical Internet infrastructures seems acceptable.

V-Recommendations

 Regarding the IPv6 PI assignment, we recommend the dissociation of the cases:

- Define the rules  for portable assignments for critical Internet infrastructures. Those recognized overall seem to be: Publics IXPs, core DNS service providers (e.g. ICANN-sanctioned root, gTLD, and ccTLD operators) as well as the RIRs and IANA.
 
- For  the IPv6 global portable assignment, consider a concerted work with the other communities which have adopted similar policy for a better communication on the issue, as /48 for end-site seems to be preferred to /32.

This work could include the standardization of the maintenance and distribution of filtering recommendations based of RIRs allocations and assignments minimum size and specific blocks used for them. An example of effort in this direction is the one published at:
http://www.space.net/~gert/RIPE/ipv6-filters.html

Acknowledgements

AIRRS project team thanks AfriNIC for its support for this work.