6rd status

Seth Mos seth.mos at dds.nl
Fri Apr 6 11:20:38 UTC 2012

Op 2-4-2012 8:54, Seth Mos schreef:
> Op 29-3-2012 16:44, Seth Mos schreef:
>> Hi,
> Only to reply to myself here, I've not seen response yet.

Replying to myself again.

I confirm that the 6rd patch to stf from hrs@ indeed works as advertised.

The Charter and Sakura 6rd relays do not employ filtering which means 
these can be used from everywhere in the world.

Sakura is about 500ms and Charter about 200ms from where I tested which 
limits the usability.

One that thing that must be noted is that the patch does not support 
RFC5969 Standards track support 6rd.

This uses a variable length for both the 6rd prefix and the v4 prefix 
length as long as it fits in the left 64 bits.

 From the RFC. http://tools.ietf.org/html/rfc5969

|     n bits    |    o bits    |   m bits  |    128-n-o-m bits      |
|  6rd prefix   | IPv4 address | subnet ID |     interface ID       |
|<--- 6rd delegated prefix --->|

There is a dutch ISP rolling out with a 6rd prefix of 41 bits and a IPv4 
prefix length of 17 bits resulting in a /56 delegated prefix for each 
user. (41 + (32 - 17)) = 56

The current 6rd patch does not provide such a facility from my limited 

Theoretically it might work providing the IPv6 prefix and gateway are 
calculated with that math in mind. But I don't have the network to 
confirm this. This might be easy to support.



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