Re: mech-v2-05pre

[Pekka Savola <pekkas@netcore.fi>]

On Thu, 26 Aug 2004, Vladislav Yasevich wrote:
> I agree.  Thus I think mandating that the packets be dropped is way
> to harsh.  Just stating that version other then 6 is outside the scope
> is fine.

As far as I see it, this is practically just a matter of semantics.

Unless we think that there's going to be another IP protocol which has
almost identical headers as IPv6 so that you'd be cable to transport
the "new" IPv6 packets (let's call them IPv11 packets just to make
sure they don't overlap with other proposals ;-) over unmodified
configured proto-41 tunnels.

On the other hand, if the IPv11 header would be significantly 
different from IPv6, there would be a need to specify a different 
configure tunneling in any case, so it doesn't matter what we specify 
in protocol-41 configured tunneling.

I somehow don't see the chance that in future we'd have to 
support almost identical new IP protocol versions over unmodified 
configured tunnels, so a drop policy seems like the most useful 
one.  It's really practically required in any case, because we require 
parsing a number of fields, like src/dst addresses, hop limit, ECN 
bits, etc.

Of course, if there's another spec down the road which modifies 
proto-41 configured tunnels behaviour somehow so that other IP 
protocols than just "6" are OK, that's fine as well.  The question is 
just about whether unmodified configured tunnels could support 
protocols other than "6", which doesn't seem to be the case..

-- 
Pekka Savola                 "You each name yourselves king, yet the
Netcore Oy                    kingdom bleeds."
Systems. Networks. Security. -- George R.R. Martin: A Clash of Kings