IPv6 routing /48s

Wed Nov 19 21:11:30 UTC 2008

Ah yes, public-but-not-external IPv4 addresses ... I wish a stern note saying don't do that was feasible ...

/TJ
------Original Message------
From: Nathan Ward
To: nanog list
Subject: Re: IPv6 routing /48s
Sent: Nov 19, 2008 15:02

On 20/11/2008, at 4:06 AM, Florian Weimer wrote:

> * Michael Sinatra:
>
>> And it just reinforces the fear that people have against putting AAAA
>> records in DNS for their publicly-accessible resources, especially
>> www.
>
> Won't current Windows clients work just fine in this case?
>
> I have no idea what a fix should look like for some of the non-Windows
> systems I care about, unfortunately.

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.

Works fine most of the time, however when that non-RFC1918 address is  
behind NAT, or some sort of packet filter, then it doesn't work so  
well, and the client does not have a way to detect that reliably.

--
Nathan Ward

Sent from my Verizon Wireless BlackBerry