2010-9 Previous Version

View the current policy proposal text.

The following version was archived on 24 September 2010.

Draft Policy 2010-9
IPv6 for 6rd

Version/Date: 20 July 2010

Policy statement:

If you have non contiguous IPv4 addresses then you automatically qualify for IPv6 space for 6rd. Upon receipt of a 6rd request, the minimum subnet required for the functionality of 6rd will be automaticlly granted and larger blocks will be granted based on justification. If IPv6 addresses are already allocated to the requestor then an effort will be made to give them an IPv6 allocation that is preferably contiguous to the prior existing one. The use of this address space will be used for 6rd and returned to ARIN when 6rd is no longer used on the network. Justification for use of IPv6 for 6rd will be reviewed every 3 years and reclaimed if it is not in use. Requestor will be exempt from returning all or a portion of the address space when 6rd is no longer used if they can show justification for need of the 6rd address space for other existing IPv6 addressing requirements.

The 6rd prefix is an RIR delegated IPv6 prefix. It must encapsulate an IPv4 address and must be short enough so that a /56 or /60 can be given to subscribers. This example shows how the 6rd prefix is created based on a /32 IPv6 prefix using RFC1918 address space from

SP IPv6 prefix: 2001:0DB8::/32
v4suffix-length: 24 (from 10/8, first octet (10) is excluded
from the encoding)
6rd CE router IPv4 address:
6rd site IPv6 prefix: 2001:0DB8:6464:0100::/56

This example shows how the 6rd prefix is created based on a /28 IPv6 prefix using one of several non-contiguous global address ranges:

SP IPv6 prefix: 2001:0DB0::/28
v4suffix-length: 32 (unable to exclude common bits
due to non-contiguous IPv4 allocations)
6rd CE router IPv4 address:
6rd site IPv6 prefix: 2001:0DBC:0000:2010::/60


6rd is intended to be an incremental method for deploying IPv6 and bridge the gap for End Users to the IPv6 Internet. The method provides a native dual-stack service to a subscriber site by leveraging existing infrastructure. If an entity already has a /32 of IPv6 they can not use the same /32 for native IPv6 as they do for the 6rd routing and a separate minimum size of a /32 is required while a larger subnet like a /28 may be needed based on a non-contiguous IPv4 addressing plan.

Timetable for implementation: Immediate