IPv6 routing /48s

Jack Bates jbates at brightok.net
Fri Nov 21 16:16:11 UTC 2008

Florian Weimer wrote:
>>> No, unfortunately broken 6to4 auto-configuration (ie, in Vista,
>>> XPSP2, when on a non-RFC1918 IP address) breaks, and you get 90s
>>> timeouts before falling back to IPv4/A.
>> This must be a broken RFC 3484 implementation:
>> - 6to4 should be less prerefed than IPv4 if the service has both AAAA
>> and A record.
> RFC 3848 generally prefers IPv6 over IPv4 and fails if the host
> running its algorithm has neither IPv6 connectivity nore mean to
> detect that efficiently.  I think Windows does something in the second
> area.

Yes and no. The test that was being run used 6to4 addresses, so every 
6to4 capable device did try to reach it via 6to4, since that is 
preferred over IPv4. If it had used non-6to4 addressing, then IPv4 would 
had been preferred on those hosts that didn't have non-6to4 addresses.

This is one reason why I believe using 6to4 addresses to be an issue for 
content providers. If they use non-6to4 addressing for the content, then 
   most people will prefer IPv4 except for those who have configured 
non-6to4 addresses or altered the labels to force 6to4 to work with 
non-6to4 addressing.

Gads, is it appropriate to just say Native when referring to non-6to4? lol


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