On Fri, Aug 5, 2011 at 12:17 PM, Brian Mengel <bmen...@gmail.com> wrote: > In reviewing IPv6 end user allocation policies, I can find little > agreement on what prefix length is appropriate for residential end > users. /64 and /56 seem to be the favorite candidates, with /56 being > slightly preferred.
Hi Brian, /64 is *strongly* discouraged. I'd go so far as to say that when we look back 3 years from now, anybody who assigned /64's to end user networks will be considered short-sighted bordering on foolish. Assign a /128 if you know the downstream is exactly 1 host (not a LAN, not a PC with virtual machines, exactly one computer) or else assign at least a /60. > I am most curious as to why a /60 prefix is not considered when trying > to address this problem. It provides 16 /64 subnetworks, which seems > like an adequate amount for an end user. Every time someone needs more than the standard assignment, you have to make a custom assignment with the manpower cost to make it and maintain it. This will happen often with /64, occasionally with /60 and rarely with /56. On the flip side, /56 allows for 16M end-users in your /32 ISP allocation. After which you can trivially get as many additional /32's as you want. Is there any reason you want to super-optimize to get 268M end-users squashed in that /32? Regards, Bill Herrin -- William D. Herrin ................ her...@dirtside.com b...@herrin.us 3005 Crane Dr. ...................... Web: <http://bill.herrin.us/> Falls Church, VA 22042-3004
