Test your connectivity for World IPv6 Day

[Fred Baker]

On Jun 6, 2011, at 1:26 PM, Rémi Després wrote:

> 
> Le 6 juin 2011 à 18:55, Fred Baker a écrit :
> 
>> 
>> On Jun 6, 2011, at 8:58 AM, Rémi Després wrote:
>> 
>>> Unless there are good reasons to know that a longer PMTU applies to all their connections, all servers SHOULD send IPv6 packets to off-link destinations with 1280 octets as default PMTU.
>>> Servers that don't do that are open for PMTU problems. 
>> 
>> I understand where you're coming from,
> 
> ???
> 
>> but I disagree.
> 
> Well, if you deny that there are operational problems with PMTUD today, you may be better informed than I am.
> 
>> I think servers and the networks supporting them need to implement PMTU. The way to do that is (pick one) RFC 4821 in TCP or to manage to not block ICMPv6.
> 
> - At least Packet-too-big ICMPv6 messages should never be blocked, agreed, but for others this isn't AFAIK as obvious. 
> - Servers that deliver valuable contents don't control where ICMPv6 may be blocked.

That's specifically why RFC 4281 is written as it is.