Re: IPv6 day and tunnels

[Jeroen Massar <jeroen () unfix org>]

On 3 Jun 2012, at 20:40, Jimmy Hess <mysidia () gmail com> wrote:

> On 6/3/12, Cameron Byrne <cb.list6 () gmail com> wrote:
> > On Sun, Jun 3, 2012 at 6:38 PM, Joe Maimon <jmaimon () ttec com> wrote:
> [snip]
> > #5  According to the IETF, MSS hacks do not exist and neither do MTU
> > issues http://www.ietf.org/mail-archive/web/v6ops/current/msg12933.html
>
> They couldn't be more wrong.  MTU issues still exist, and not just
> with tunnelling,
> but tunneling should be an expected scenario for IP.
>
> The protocol IPv6 still handles it very poorly,  by still requiring
> external ICMP messages,
> through the  unreliable PTMUD scheme,  matters are as bad if not worse
> than with IPv4.

As ICMPv6 is an integral part of IPv6 how exactly is ICMP "external"?
You do realize what the function of ICMP is I hope?

If one is so stupid to just block ICMP then one should also accept that one loses functionality.

If the people in the IETF would have decided to inline the headers that are ICMPv6 into the IPv6 header then there for 
sure would have been people who would have blocked the equivalent of PacketTooBig in there too. As long as people can 
block stuff they will block stuff that they should not have blocked, nothing the IETF can do about, stupidity exists 
behind the keyboard.

That said, pMTU discovery works awesomely in the 10+ years that I have been actively been using IPv6, if it does no 
work for you, find the issue and resolve it. (tracepath is a great tool for this btw)

> It's just so unfortunate that IPv6 couldn't provide a good solution
> to one of IP's more troublesome deficiencies.

Did you ever bother to comment about your supposed issue in the IETF?

Greets,
 Jeroen