IPv6 day and tunnels

Mon Jun 4 14:31:28 UTC 2012

On Jun 4, 2012, at 10:07 AM, Jeroen Massar wrote:

> On 4 Jun 2012, at 06:36, Masataka Ohta <mohta at necom830.hpcl.titech.ac.jp> wrote:
> 
>> Jeroen Massar wrote:
>> 
>>>>> So IPv6 fixes the fragmentation and MTU issues of IPv4 by how exactly?
>>>> 
>>>> Completely wrongly.
>>> 
>>> Got a better solution? ;)
>> 
>> IPv4 without PMTUD, of course.
> 
> We are (afaik) discussing IPv6 in this thread, I assume you typo'd here ;)

He is comparing & contrasting with the behavior of IPv4 v IPv6.

If your PMTU is broken for v4 because people do wholesale blocks of ICMP, there is a chance they will have the same problem with wholesale blocks of ICMPv6 packets.

The interesting thing about IPv6 is it's "just close enough" to IPv4 in many ways that people don't realize all the technical details.  People are still getting it wrong with IPv4 today, they will repeat their same mistakes in IPv6 as well.

-

I've observed that if you avoid providers that rely upon tunnels, you can sometimes observe significant performance improvements in IPv6 nitrates.  Those that are tunneling are likely to take a software path at one end, whereas native (or native-like/6PE) tends to not see this behavior.  Those doing native tend to have more experience debugging it as well as they already committed business resources to it.

- Jared