Hello; I think that people here would be interested in (and likely concerned by) the ARIN 2010-9 proposal : https://www.arin.net/policy/proposals/2010_9.html "On 15 July 2010 the ARIN Advisory Council (AC) selected "IPv6 for 6rd" as a draft policy for adoption discussion on the PPML and at the Public Policy Meeting in Atlanta in October. IPv6 for 6rd 6rd is an incremental method for Service Providers to deploy IPv6, defined in the IETF Standards Track RFC 5969. 6rd has been used successfully by a number of service providers to deploy IPv6 based on automatic IPv6 prefix delegation and tunneling over existing IPv4 infrastructure. .... " What worries me (and others) is that to give end users an IPv6 /56 will generally require the assignments as short as /24s to ISPs, due to the encapsulation of v4 addresses inside of v6 addresses : "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." 56 - 32 = a /24 If every ISP or other such entity has to get a /24, then there is room for 2^21 or two million such entities. If, as seems likely, ISP assignments to users grow to /48's, then the ISP will need a /16, and that room shrinks dramatically. Based on this, I (and a bunch of other people on the ARIN PPML list) oppose this. I thought it would be wise to bring this to the attention of the wider IETF community. ARIN discussion of this matter of course is going on on the arin-ppml@xxxxxxxx list. Regards Marshall _______________________________________________ Ietf mailing list Ietf@xxxxxxxx https://www.ietf.org/mailman/listinfo/ietf