Re: mech-v2-05pre

[Pekka Savola <pekkas@netcore.fi>]

On Wed, 25 Aug 2004, Vladislav Yasevich wrote:
> Wouldn't the version check be part of the standard IPv6 processing?
> Why do we want to mandate it here as well?
> 
> I can see the need to make sure that we have enough data, so the
> decapsulator may want to check that it has at least 40 bytes of
> payload, but the version check seems redundant to me.

Well.. folks asked for the version check..

I can see a justification in the sense that AFAIK it's not strictly 
necessary to check the IP version when processing the packets, because 
the lower layer (ethernet protocol type, protocol 41, etc.) already 
indicated the ip version of the payload.  When using a tunnel, the 
chance of someone sending packets which aren't really IPv6 but using 
proto-41 (or the like) seems significantly larger than e.g., using 
Ethernet.

So, in that sense, both checks are redundant, just spelling out checks 
which should be done for IPv6 packets in any case, but I don't think 
it hurts to have them here.

If other set of folks think it's bad idea to have them here, we could
just remove the paragraph (and it would be as it was before), or add 
something like, "As with processing any other IPv6 packet received 
from link-layers, ...." to clarify that this particular link layer 
should not be special...

Thoughts?

Note: I already submitted -05 with the change.

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