From the dualstack-is-fun department...

Andrew Yourtchenko ayourtch at
Wed Mar 2 00:39:13 CET 2011

On Tue, Mar 1, 2011 at 7:04 PM, Cameron Byrne <cb.list6 at> wrote:
> On Tue, Mar 1, 2011 at 9:28 AM, Andrew Yourtchenko <ayourtch at> wrote:
>> On Tue, Mar 1, 2011 at 4:49 PM, Cameron Byrne <cb.list6 at> wrote:
>>> On Tue, Mar 1, 2011 at 4:29 AM, Andrew Yourtchenko <ayourtch at> wrote:

[ lots of stuff snip, Touche re. IE6. It's actually ~5% now but still
noticeable. Thanks for the vid - loved to see it again. ]

> me of recent v6ops flame war where the co-creator of 6to4 refused to
> admit that 6to4 was ever an issue and could possibly in any way harm
> v6 deployment.

I am sorry if I made myself sound like in a flame war - that was not
the intent at all.

> I am not saying HE is bad in any way,
> i am just saying we need to go real slow and be VERY grounded in reality.
> The only way i can think to do that is to add MUST NOT be on by default.
> HE is a good work-around *NOT A FIX* for broken connections.... and masking issues
> is only ok for a short time if we are really going to follow-up and
> fix it.  That said, lets wait for symptoms before applying the
> tourniquet, and yes, HE is a tourniquet... but hopefully only cutting
> off circulation on a per destination basis for a short amount of time.

What do you think about this:

      Some sites may wish to be informed when the the hosts adjust
their "P" value,
      in order to troubleshoot the underlying cause. To help these sites,
      a strawman proposal is to send a syslog message or other notification
      to an address that may be configured
      by a site administrator in a centralized fashion.
      (The exact method TBD - DHCP option, domain name, etc.)
      This syslog message should be sent only first N times that the host
      expects to prefer IPv6 but has to use IPv4. I.e. the first N
times it decreases
      the value of P. The value of N TBD.

This should make HE into something that can *lower* the complexity of
the troubleshooting ?

If you have the HE at the end user = you configure them to send a
notification to your helpdesk proactively;

If you have it at a helpdesk - you convert this into a big flashing
"That site you just tested, does not work over IPv6.
We made it work because we are so kind to quickly fallback - but IE6
will be broken...."


> Cameron

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